JP-3687: fix outlier_detection failures when run outside pipeline

[emolter]

Resolves JP-3687

Closes #8640

This PR addresses a bug that occurs when the outlier_detection step is run outside the pipeline, i.e., loading the datamodel from file instead of passing it in as a ModelContainer. In that case, the wcs.array_shape attribute sometimes does not get saved (saving of this attribute was added to gwcs within the past year, so the behavior is version-dependent). This PR sets the wcs.array_shape explicitly.

Checklist for PR authors (skip items if you don't have permissions or they are not applicable)

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

[emolter]

Regression tests started here, using the new GitHub Actions workflow (hope that works!) https://github.com/spacetelescope/RegressionTests/actions/runs/9940607341

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 59.61%. Comparing base (4b77a5e) to head (d433757).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #8645 +/- ## ======================================= Coverage 59.60% 59.61% ======================================= Files 391 391 Lines 39286 39287 +1 ======================================= + Hits 23418 23419 +1 Misses 15868 15868 ```

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[emolter]

separate regtests with same changes started here on Jenkins: https://plwishmaster.stsci.edu:8081/job/RT/job/JWST-Developers-Pull-Requests/1605/

[emolter]

all regtest failures are unrelated