add pytest_crds as an entrypoint

[zacharyburnett]

moves pytest_crds plugin from jwst to here. pytest_crds is a PyTest plugin that reports the CRDS context in the pytest output if you add the --report-crds-context flag

corresponding PR in jwst:

• remove pytest_crds plugin jwst#9001

Tasks

• update or add relevant tests
• update relevant docstrings and / or docs/ page
• Does this PR change any API used downstream? (if not, label with no-changelog-entry-needed)
  • write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see below for change types)
  • run regression tests with this branch installed ("git+https://github.com/<fork>/stpipe@<branch>")
    • jwst regression test
    • romancal regression test

news fragment change types...

• changes/<PR#>.feature.rst: new feature
• changes/<PR#>.bugfix.rst: fixes an issue
• changes/<PR#>.doc.rst: documentation change
• changes/<PR#>.removal.rst: deprecation or removal of public API
• changes/<PR#>.misc.rst: infrastructure or miscellaneous change

[codecov]

Codecov Report

Attention: Patch coverage is 28.57143% with 5 lines in your changes missing coverage. Please review.

Project coverage is 95.08%. Comparing base (a2a8d46) to head (11fbb09).
Report is 44 commits behind head on main.

Files with missing lines	Patch %	Lines
src/stpipe/pytest_crds/plugin.py	28.57%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #211      +/-   ##
==========================================
- Coverage   95.22%   95.08%   -0.15%     
==========================================
  Files          37       38       +1     
  Lines        3165     3172       +7     
==========================================
+ Hits         3014     3016       +2     
- Misses        151      156       +5     

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[braingram]

As this package is used by romancal (and we've heard about uses for other projects) I think jwst (or another package) is the right home for this plugin (if the plugin is still useful).

EDIT: after discussion about potential usefulness for roman my vote is to update this PR to be compatible with both packages and for uses where crds might not be used.

[pllim]

Why not just always enable the reporting? Not like romancal can run without CRDS. I don't think you need a whole plugin to just control a test header.

[pllim]

Shouldn't be "jwst" anymore here if you decide to keep it?