Removed pkg_resources from test_wheel.

[jaraco]

• Remove test_wheel_install_pep_503.
• Remove reliance on pkg_resources in test_wheel.
• Add news fragment.

Summary of changes

Ref #3085

Pull Request Checklist

• Changes have tests
• News fragment added in newsfragments/.
  (See documentation for details)

[jaraco]

There are tests failing in test_cygwin and test (pypy), but they're unrelated to these changes and they seem to fail intermittently. I'm going to proceed with this change.

[jaraco]

Oh, but the pyright stuff should probably be addressed.

[jaraco]

The pyright tests are failing now that I'm using importlib.metadata for the metadata and __getitem__ in older versions of the package could possibly return None. I don't care. I want them to crash or fail if the keys aren't present. I'll just try to suppress the pyright errors.