ci: #3625830 Keep the CI build below Twig 3.30

Issue: https://www.drupal.org/i/3625830

Changes

1.0.x went red (https://git.drupalcode.org/project/ai_figma/-/pipelines/977050): the Drupal Canvas AI lane resolved Twig 3.30.0, which compiles core's drupal_escape filter into a direct EscaperRuntime::escape() call, so every page render is a fatal TypeError and all 22 scenarios fail on 500 Service unavailable. The Display Builder AI lane got Twig 3.28.0 and passed 22/22.

This pins twig/twig:<3.30 in CI only: the templates composer build via .composer-base, and the varbase-e2e site build's composer require. The module's composer.json is untouched. Remove it once a fixed Twig is out. Same fix as ai_agent_modes!17 (merged).

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

🤖 Generated with Claude Code