task: #3635746 Update Node.js to >= 24.0 and Yarn to 4.18.1

Moves the Node.js pins on 5.0.x to 24, the floor Drupal core main declares in core/package.json. Node.js 20 reached end of life on 30 April 2026.

Issue: https://www.drupal.org/i/3635746

• engines: node >= 24.0, yarn >= 4.18.1; packageManager yarn@4.18.1.
• House .yarnrc.yml, .yarn/ ignored.
• CI: NodeSource setup_24.x for the browser tests; gitlab-ci-local node:24.
• CI: keep Drupal core Yarn off .yarnrc.yml on .composer-base and stylelint.
• test scripts call the cucumber.js entry: Yarn 4 does not expose cucumber-js to yarn run.
• Remove the Yarn Classic yarn.lock and ignore JavaScript lockfiles.
• Caret dependency ranges, as Drupal core does.
• CI: pin DRUPAL_CORE to 11.4.11 on the composer job. Templates 1.17.0 resolve CORE_STABLE to 11.4.6, which Twig 3.30 breaks (HTTP 500 on every rendered page, fixed in core 11.4.8), so all six browser scenarios failed at the login form.

Checked in node:24 (v24.22.2) with no lockfile present: the Yarn 4.18.1 install, the test dry run (6 scenarios) and gitlab-ci-local cspell pass. MR pipeline 1033895 is green, all 8 jobs.

AI-Generated: Yes

Checkpoints:

• File an issue
• Addition/Change/Update/Fix
• Testing to ensure no regression
• Automated unit testing coverage
• Automated functional testing coverage
• UX/UI designer responsibilities
• Readability
• Accessibility
• Performance
• Security
• Developer Documentation
• User Guide Documentation
• Reviewed by human
• Code review by maintainers
• Full testing and approval
• Credit contributors
• Review with the product owner
• Release notes snippet
• Release