One last webbpsf/stpsf change, cleanup warnings, remove unused file

[braingram]

This PR:

• updates one more WEBBPSF_PATH environment variable reference (in tox.ini to pass the new environment variable to the pytest runs)
• removes the JenkinsRT_dev file (regression tests are now run at https://github.com/spacetelescope/RegressionTests/actions/workflows/romanisim.yml)
• increases the gwcs minimum version to 0.20.0 and crds to 11.16.21 to silence the pkg_resources warning in oldestdeps

I attempted to turn warnings into errors but a few tests failed with resource warnings (due to open files):
https://github.com/spacetelescope/romanisim/actions/runs/13392587089/job/37403626586?pr=206
So I removed that filter change.

With this PR the unit tests now run without webbpsf/stpsf data warnings:
https://github.com/spacetelescope/romanisim/actions/runs/13393139977/job/37405428093?pr=206#step:10:205

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.85%. Comparing base (244858c) to head (188d6a2).
Report is 16 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #206      +/-   ##
==========================================
- Coverage   90.02%   89.85%   -0.18%     
==========================================
  Files          17       17              
  Lines        2165     2178      +13     
==========================================
+ Hits         1949     1957       +8     
- Misses        216      221       +5     

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[schlafly]

Ugh, sorry---thank you!