Fix test_e2e_python by specifying Python loader in config (#20273)

Author: Pierre-L42

snmp/tests/test_e2e_python.py

@@ -15,6 +15,7 @@
 def test_e2e_python(dd_agent_check):
     metrics = common.SUPPORTED_METRIC_TYPES
     config = common.generate_container_instance_config(metrics)
+    config['init_config']['loader'] = 'python'
     instance = config['instances'][0]
     aggregator = dd_agent_check(config, rate=True)
     tags = ['snmp_device:{}'.format(instance['ip_address'])]