Add .gitlab-ci.yml

Opened an MR that adds a basic .gitlab-ci.yml. It sets OPT_IN_TEST_CURRENT to 0 because we don't support Drupal 11 yet (see 📌 Automated Drupal 11 compatibility fixes for jsonapi_schema Needs review ), and sets OPT_IN_TEST_PREVIOUS_MAJOR to 1 to run tests (just linting) against Drupal 10.

composer-lint and eslint tests pass, but cspell and phpcs do not. Setting to Needs Work to work on those.

There are two misspelled words flagged by cspell

CSpell: Files checked: 27, Issues found: 5 in 5 files.
The number of distinct unrecognised/misspelled words is 2
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millisec
shema
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"shema" is fixed by #3324620: Fix plugin ID typo: s/shema/schema/ → and "millisec" is fixed by #3246251: Change format "utc-millisec" to "date-time" → , so I think we can hold off on fixing those here.

Pushed a bunch of commits that fix all phpcs warnings and errors.

They are almost entirely comment and whitespace changes.

It's also an opportunity to run phpstan

It seems that phpstan isn't running automatically. I am going to punt that out to a separate issue.

This should be ready to merge.

Merged.

It seems that phpstan isn't running automatically. I am going to punt that out to a separate issue.

Created a follow-up issue: 📌 Fix PHPStan errors Active

Automatically closed - issue fixed for 2 weeks with no activity.