Simplify bash unsupported markers

[kenodegard]

Description

The skipif markers for whether a bash flavored test_activate.py test can run is overly verbose. This creates reusable markers for easy usage.

before	after
@pytest.mark.skipif( bash_unsupported(), reason=bash_unsupported_because(), ) def test_foo(...): ...	@skip_unsupported_bash def test_foo(...): ...
@pytest.mark.skipif( bash_unsupported_win(), reason=bash_unsupported_win_because(), ) def test_bar(...): ...	@skip_unsupported_posix_path def test_bar(...): ...

Split from #13620

Checklist - did you ...

• Add a file to the news directory (using the template) for the next release's release notes?
• Add / update necessary tests?
• Add / update outdated documentation?

[codspeed-hq]

CodSpeed Performance Report

Merging #13738 will not alter performance

_{Comparing kenodegard:simplify-skipif-unsupported-bash (899fefa) with main (11c21d5)}

Summary

✅ 21 untouched benchmarks