Add read pattern test.

[schlafly]

This PR adds a new test to make sure that read_pattern is propagated into catalogs / segmentation maps. It is a nested arrays and so there is some roman_datamodels handling that can cause problems.

Only adds a unit test (which should fail). Regtests pointing to spacetelescope/roman_datamodels#692 should pass:
https://github.com/spacetelescope/RegressionTests/actions/runs/29610396350

Tasks

• request a review from someone specific, to avoid making the maintainers review every PR
• add a build milestone, i.e. 24Q4_B15 (use the latest build if not sure)
• Does this PR change user-facing code / API? (if not, label with no-changelog-entry-needed)
  • write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see changelog readme for instructions)
    • if your change breaks existing functionality, also add a changes/<PR#>.breaking.rst news fragment
  • update or add relevant tests
  • update relevant docstrings and / or docs/ page
• if a JIRA ticket exists, make sure it is resolved properly

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.82%. Comparing base (4536045) to head (4390de8).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2390   +/-   ##
=======================================
  Coverage   82.82%   82.82%           
=======================================
  Files         131      131           
  Lines        7249     7249           
=======================================
  Hits         6004     6004           
  Misses       1245     1245           

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[schlafly]

@braingram or @WilliamJamieson , any interest reviewing? This PR just adds a unit test that currently fails; when copying metadata into the source catalog or segmentation map from the L2 image, some array fields do not survive. This test demonstrates that problem. spacetelescope/roman_datamodels#692 intends to fix the issue. That does work; the regression test run
https://github.com/spacetelescope/RegressionTests/actions/runs/29610396350
passes. But I haven't looked carefully at the roman_datamodels code I'm changing.

[braingram]

Should we consider #2237 so we can compare the truth metadata to the regtest results?

[schlafly]

Ugh, sorry I lost #2237. Let me respond in the thread there about that one...