Missing test data in source distribution

[mgorny]

As of 0.22.1, the tests/certs and tests/proc directories are missing from the source distribution, which leads to test failures:

$ pytest
========================================================= test session starts =========================================================
platform linux -- Python 3.13.3, pytest-8.4.0, pluggy-1.6.0
rootdir: /tmp/prometheus_client-0.22.1
configfile: pyproject.toml
collected 253 items                                                                                                                   

tests/test_asgi.py ssssssss                                                                                                     [  3%]
tests/test_core.py .........................................................................................................    [ 44%]
tests/test_exposition.py ............................F..............................                                            [ 67%]
tests/test_gc_collector.py ..                                                                                                   [ 68%]
tests/test_graphite_bridge.py .......                                                                                           [ 71%]
tests/test_multiprocess.py .............................                                                                        [ 83%]
tests/test_parser.py ...........................                                                                                [ 93%]
tests/test_platform_collector.py ..                                                                                             [ 94%]
tests/test_process_collector.py FFF.                                                                                            [ 96%]
tests/test_samples.py ..                                                                                                        [ 96%]
tests/test_twisted.py s                                                                                                         [ 97%]
tests/test_wsgi.py .......                                                                                                      [100%]

============================================================== FAILURES ===============================================================
___________________________________________ TestPushGateway.test_push_with_tls_auth_handler ___________________________________________

self = <test_exposition.TestPushGateway testMethod=test_push_with_tls_auth_handler>

    def test_push_with_tls_auth_handler(self):
        def my_auth_handler(url, method, timeout, headers, data):
            certs_dir = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'certs')
            return tls_auth_handler(url, method, timeout, headers, data, os.path.join(certs_dir, "cert.pem"), os.path.join(certs_dir, "key.pem"))
    
>       push_to_gateway(self.address, "my_job_with_tls_auth", self.registry, handler=my_auth_handler)

tests/test_exposition.py:362: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
prometheus_client/exposition.py:554: in push_to_gateway
    _use_gateway('PUT', gateway, job, registry, grouping_key, timeout, handler)
prometheus_client/exposition.py:646: in _use_gateway
    handler(
tests/test_exposition.py:360: in my_auth_handler
    return tls_auth_handler(url, method, timeout, headers, data, os.path.join(certs_dir, "cert.pem"), os.path.join(certs_dir, "key.pem"))
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

url = 'http://localhost:44163/metrics/job/my_job_with_tls_auth', method = 'PUT', timeout = 30
headers = [('Content-Type', 'text/plain; version=0.0.4; charset=utf-8')], data = b'# HELP g help\n# TYPE g gauge\ng 0.0\n'
certfile = '/tmp/prometheus_client-0.22.1/tests/certs/cert.pem', keyfile = '/tmp/prometheus_client-0.22.1/tests/certs/key.pem'
cafile = None, protocol = <_SSLMethod.PROTOCOL_TLS_CLIENT: 16>, insecure_skip_verify = False

    def tls_auth_handler(
            url: str,
            method: str,
            timeout: Optional[float],
            headers: List[Tuple[str, str]],
            data: bytes,
            certfile: str,
            keyfile: str,
            cafile: Optional[str] = None,
            protocol: int = ssl.PROTOCOL_TLS_CLIENT,
            insecure_skip_verify: bool = False,
    ) -> Callable[[], None]:
        """Handler that implements an HTTPS connection with TLS Auth.
    
        The default protocol (ssl.PROTOCOL_TLS_CLIENT) will also enable
        ssl.CERT_REQUIRED and SSLContext.check_hostname by default. This can be
        disabled by setting insecure_skip_verify to True.
    
        Both this handler and the TLS feature on pushgateay are experimental."""
        context = ssl.SSLContext(protocol=protocol)
        if cafile is not None:
            context.load_verify_locations(cafile)
        else:
            context.load_default_certs()
    
        if insecure_skip_verify:
            context.check_hostname = False
            context.verify_mode = ssl.CERT_NONE
    
>       context.load_cert_chain(certfile=certfile, keyfile=keyfile)
E       FileNotFoundError: [Errno 2] No such file or directory

prometheus_client/exposition.py:503: FileNotFoundError
_________________________________________________ TestProcessCollector.test_namespace _________________________________________________

self = <test_process_collector.TestProcessCollector testMethod=test_namespace>

    def test_namespace(self):
        collector = ProcessCollector(proc=self.test_proc, pid=lambda: 26231, registry=self.registry, namespace='n')
        collector._ticks = 100
        collector._pagesize = 4096
    
>       self.assertEqual(17.21, self.registry.get_sample_value('n_process_cpu_seconds_total'))
E       AssertionError: 17.21 != None

tests/test_process_collector.py:30: AssertionError
__________________________________________________ TestProcessCollector.test_working __________________________________________________

self = <test_process_collector.TestProcessCollector testMethod=test_working>

    def test_working(self):
        collector = ProcessCollector(proc=self.test_proc, pid=lambda: 26231, registry=self.registry)
        collector._ticks = 100
        collector._pagesize = 4096
    
>       self.assertEqual(17.21, self.registry.get_sample_value('process_cpu_seconds_total'))
E       AssertionError: 17.21 != None

tests/test_process_collector.py:17: AssertionError
________________________________________________ TestProcessCollector.test_working_584 ________________________________________________

self = <test_process_collector.TestProcessCollector testMethod=test_working_584>

    def test_working_584(self):
        collector = ProcessCollector(proc=self.test_proc, pid=lambda: "584\n", registry=self.registry)
        collector._ticks = 100
        collector._pagesize = 4096
    
>       self.assertEqual(0.0, self.registry.get_sample_value('process_cpu_seconds_total'))
E       AssertionError: 0.0 != None

tests/test_process_collector.py:43: AssertionError
======================================================= short test summary info =======================================================
FAILED tests/test_exposition.py::TestPushGateway::test_push_with_tls_auth_handler - FileNotFoundError: [Errno 2] No such file or directory
FAILED tests/test_process_collector.py::TestProcessCollector::test_namespace - AssertionError: 17.21 != None
FAILED tests/test_process_collector.py::TestProcessCollector::test_working - AssertionError: 17.21 != None
FAILED tests/test_process_collector.py::TestProcessCollector::test_working_584 - AssertionError: 0.0 != None
============================================== 4 failed, 240 passed, 9 skipped in 4.19s ===============================================

[mgorny]

This is a regression from b0a6f12 which removed MANIFEST.in.