Fix skip in entrypoints backport tests

[QuLogic]

If importlib_metadata is not installed, then you get an error in collection:

Using pytest.skip outside of a test will skip the entire module. If that's your intention, pass `allow_module_level=True`. If you want to skip a specific test or an entire class, use the @pytest.mark.skip or @pytest.mark.skipif decorators.

• [x] Unit tests and/or doctests in docstrings
• [x] Tests pass locally
• [n/a] Docstrings and API docs for any new/modified user-facing classes and functions
• [x] Changes documented in docs/release.rst
• [x] Docs build locally
• [x] GitHub Actions CI passes
• [x] Test coverage to 100% (Codecov passes)

[joshmoore]

Many thanks, @QuLogic!