task: Add GitLab CI on Drupal 11.4 and PHP 8.4

Problem/Motivation

The Website Starter recipe has no GitLab CI, so merge requests get no check that the recipe still resolves with Composer, passes cspell, and applies on a fresh site.

Steps to reproduce

1. Open a merge request against 1.0.x.
2. No pipeline runs.

Proposed resolution

Add a .gitlab-ci.yml on the drupal.org GitLab templates, with Drupal 11.4.x-dev and PHP 8.4:

• composer, composer-lint and cspell (the exported demo content is not spell-checked).
• A recipe job: drush site:install recipes/website_starter, then check that the default theme is ui_suite_uikit and that the demo content was imported.
• Skip PHPCS, PHPStan, PHPUnit, ESLint and Stylelint: the recipe has no PHP, CSS or tests.

Remaining tasks

• ✅ File an issue about this project
• ❌ Addition/Change/Update/Fix to this project
• ❌ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ❌ Reviewed by a human
• ❌ Code review by maintainers
• ❌ Full testing and approval
• ❌ Credit contributors
• ❌ Review with the product owner
• ❌ Update Release Notes
• ❌ Release

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• N/A

AI-Generated: Yes