Force array validation when initializing a datamodel from another datamodel of different type

[emolter]

Closes #307

This PR fixes a bug that allowed initialization of a datamodel from a different datamodel with an incompatible schema. For example, a CubeModel could be used as input to an ImageModel, e.g., model = ImageModel(CubeModel(10,10,10)), leading to a situation where the ImageModel contained a 3-D data array that was incompatible with its schema ndim. This PR forces validation of arrays when attempting this kind of assignment.

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 jwst regression tests with this branch installed ("git+https://github.com/<fork>/stdatamodels@<branch>")

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

[emolter]

jwst regression tests https://github.com/spacetelescope/RegressionTests/actions/runs/13311698850

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.42%. Comparing base (4e83608) to head (eeb3401).
Report is 6 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #403      +/-   ##
==========================================
+ Coverage   78.16%   78.42%   +0.25%     
==========================================
  Files         115      115              
  Lines        5144     5155      +11     
==========================================
+ Hits         4021     4043      +22     
+ Misses       1123     1112      -11     

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[emolter]

Failing JWST regression tests are due to one instance that took advantage of this bug to initialize a CubeModel with an ImageModel. So this PR is blocked until spacetelescope/jwst#9192 is merged

[emolter]

@jdavies-st this is the other fix associated with the validation issue you raised a while back, please feel free to review if you are interested

[jdavies-st]

Changes look good.

A meta question is why are there are tree of tests under src? The whole point of the src layout is to separate the package from the tests dir and not have the tests there, as recommended by Python packaging guides for the last decade and by pytest.

[tapastro]

Pytest describes both options as valid here, including a method involving both: https://docs.pytest.org/en/7.1.x/explanation/goodpractices.html#choosing-a-test-layout-import-rules

Placing unit tests in subdirectories inline with their source follows jwst convention and makes it clear which tests are meant to cover which code. I don't see a overruling reason to extricate test files from src/stdatamodels/jwst/{datamodels/transforms}.

[braingram]

LGTM.