Fix types and type linting

Author: sigmavirus24

Diff for: twine/cli.py

@@ -118,6 +118,6 @@ def dispatch(argv: List[str]) -> Any:
 
     configure_output()
 
-    main = registered_commands[args.command].load()  # type: ignore[no-untyped-call] # python/importlib_metadata#288  # noqa: E501
+    main = registered_commands[args.command].load()
 
     return main(args.args)

Diff for: twine/wheel.py

@@ -16,6 +16,7 @@
 import re
 import zipfile
 from typing import List, Optional
+from typing import cast as type_cast
 
 from pkginfo import distribution
 
@@ -87,5 +88,7 @@ def parse(self, data: bytes) -> None:
         super().parse(data)
 
         fp = io.StringIO(data.decode("utf-8", errors="replace"))
+        # msg is ``email.message.Message`` which is a legacy API documented
+        # here: https://docs.python.org/3/library/email.compat32-message.html
         msg = distribution.parse(fp)
-        self.description = msg.get_payload()
+        self.description = type_cast(str, msg.get_payload())