3.0.x has no GitLab CI: merge requests and commits get no pipeline

Problem/Motivation

The 3.0.x branch has no GitLab CI configuration. It is the branch that supports Drupal 10 and 11, so it is the branch nearly every site running this module is on — and nothing on it is verified automatically. Merge requests get no pipeline, and maintainer commits get no pipeline. Everything that has landed recently was verified only by whatever the contributor happened to run on their own machine.

By contrast, 4.0.x (the Drupal 12 branch) picked up a working .gitlab-ci.yml during the Drupal 12 compatibility work and does run pipelines on every push and merge request.

Steps to reproduce

1. No CI configuration on 3.0.x. The root of 3.0.x carried only the retired DrupalCI configuration (drupalci.yml plus a stray drupalci.yml_.txt), while 4.0.x has .gitlab-ci.yml. DrupalCI was decommissioned in 2023, so those files do nothing.

2. No pipeline had ever run for 3.0.x. Both /merge_requests/14/pipelines and /pipelines?ref=3.0.x returned an empty array. All 24 pipelines in the project belonged to 4.0.x refs.

3. Even with CI, 3.0.x would have executed zero tests. Its two test files were named with a plural Tests suffix, which PHPUnit's *Test.php discovery never collects. Worse, the Drupal Association template gates the phpunit job on exists: '**/tests/**/*Test.php', so the job would not have been created at all and the pipeline would have gone green with one fewer job. MR !14 fixed the naming.

4. Recent fixes landed with no automated verification. Commit 039cb78 (issue 3531242) and MR !14 (issue 3614068) both went in without a pipeline.

Proposed resolution

Add a .gitlab-ci.yml to 3.0.x modelled on 4.0.x's, but without the Drupal-12-specific overrides (the job-level DRUPAL_CORE: $CORE_MAJOR_DEVELOPMENT, _TARGET_PHP: $CORE_NEXT_PHP_MIN, IGNORE_PROJECT_DRUPAL_CORE_VERSION and MINIMUM_STABILITY_OVERRIDE). This branch declares core_version_requirement: ^10 || ^11, so it should take the template defaults for both core and PHP. Also delete drupalci.yml and drupalci.yml_.txt.

Two variables are not what you would expect, and both were discovered the hard way while implementing this. See comments below for the full diagnosis; the short version:

• _PHPUNIT_TESTGROUPS must be '--all', not 'layout_builder_kit'. PHPUnit 10 and later ignore doc-comment metadata on any class that carries at least one PHP attribute. The Kernel classes carry #[RunTestsInSeparateProcesses], so their @group annotation was invisible under Drupal 11 and a --group run collected 2 tests instead of 12. Drupal 10's PHPUnit 9 has no attribute support at all, so it still read the annotation and collected all 12 — the two majors disagreeing is what exposed the bug. '--all' is the template's value meaning "add no --group filter"; the invocation is already scoped to the module directory.
• OPT_IN_TEST_PREVIOUS_MAJOR: '1' is not sufficient on its own. _AUTORUN_PREVIOUS_MAJOR defaults to none, which leaves the Drupal 10 jobs as manual stubs that never run — indistinguishable from real D10 coverage unless you look. Both variables are required.

The working configuration:

include:
  - project: $_GITLAB_TEMPLATES_REPO
    ref: $_GITLAB_TEMPLATES_REF
    file:
      - '/includes/include.drupalci.main.yml'
      - '/includes/include.drupalci.variables.yml'
      - '/includes/include.drupalci.workflows.yml'

variables:
  SKIP_NIGHTWATCH: '1'
  _PHPUNIT_TESTGROUPS: '--all'
  OPT_IN_TEST_PREVIOUS_MAJOR: '1'
  _AUTORUN_PREVIOUS_MAJOR: 'all'

Remaining tasks

• Review and merge MR !16.
• The advisory lint jobs (phpcs, phpstan, stylelint, eslint) fail on pre-existing debt. They are allow_failure: true so nothing blocks. Cleaning them up and only then making each one gate is tracked separately in #3614242.
• Once this lands, rebase #3614245's MR !17 so the Book Navigation fix gets a real pipeline on both majors rather than local verification only.

Scope note

MR !16 grew beyond adding CI, deliberately. Turning CI on is only worth something if it runs the tests, and two problems had to be fixed before it did:

• LayoutBuilderKitUITest assigned $this->adminUser without declaring the property. On PHP 8.2+ that is a deprecation, Drupal's PHPUnit configuration treats printed output as risky, and the job exits non-zero. Drupal 10 runs PHP 8.1 and never saw it, so this was Drupal 11 only.
• #[Group('layout_builder_kit')] was added to the Kernel classes so a --group run also works, alongside the retained @group docblocks for PHPUnit 9.

It also backports the unit and kernel tests that only existed on 4.0.x, taking the branch from 12 collected tests to 28, and ports a trimmed .cspell.json so that job produces a real signal rather than permanent advisory noise.