[CI] run pip list after installing override requirements in Jenkins

[zacharyburnett]

analogous to spacetelescope/romancal#711 (review)

Currently the pip freeze happens after the initial dependency install, but before the OVERRIDE_REQUIREMENTS option is handled by Jenkins. This makes it difficult to see if Jenkins has successfully installed an overriden requirement for the test run. This PR adds an additional pip list (same as pip freeze just more nicely formatted as a table) after the OVERRIDE_REQUIREMENTS are applied so that one can check in the Jenkins job log to make sure overriden requirements have successfully installed.

Checklist for maintainers

• added entry in CHANGES.rst within the relevant release section
• updated or added relevant tests
• updated relevant documentation
• added relevant milestone
• added relevant label(s)
• ran regression tests, post a link to the Jenkins job below.
  How to run regression tests on a PR
• Make sure the JIRA ticket is resolved properly

[zacharyburnett]

regtest job running at https://plwishmaster.stsci.edu:8081/blue/organizations/jenkins/RT%2FJWST-Developers-Pull-Requests/detail/JWST-Developers-Pull-Requests/734/pipeline with the following override:

requests>1.0.0

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -0.01 ⚠️

Comparison is base (c20b833) 77.48% compared to head (da3288a) 77.48%.

❗ Current head da3288a differs from pull request most recent head baad926. Consider uploading reports for the commit baad926 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7596      +/-   ##
==========================================
- Coverage   77.48%   77.48%   -0.01%     
==========================================
  Files         456      456              
  Lines       36592    36591       -1     
==========================================
- Hits        28355    28354       -1     
  Misses       8237     8237              

Flag	Coverage Δ		*Carryforward flag
nightly	77.54% <ø> (ø)		Carriedforward from 21c7b51

*This pull request uses carry forward flags. Click here to find out more.

see 1 file with indirect coverage changes

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[zacharyburnett]

pip list successfully showed the additional requirement: https://plwishmaster.stsci.edu:8081/blue/organizations/jenkins/RT%2FJWST-Developers-Pull-Requests/detail/JWST-Developers-Pull-Requests/734/pipeline/121#step-192-log-72