Add Symfony 8, PHP 8.5 support and migrate from deprecated XML config to PHP/YAML

[HecFranco]

Summary

This PR prepares LiipMonitorBundle for Symfony 8 and PHP 8.5 while maintaining full backward compatibility with Symfony 6.4 and 7.x. It also addresses the XML configuration deprecation introduced in Symfony 7.4.

Changes

1. Replace deprecated XML configuration (Symfony 7.4+ compatibility)

• Service definitions: Migrated all service configuration from XML to PHP format
  • Core services: runner, helper, commands, controller, symfony_mailer
  • All 33 check definitions in Resources/config/checks/
• Routing: Migrated from routing.xml to routing.yaml
• Loaders: Updated LiipMonitorExtension and MailerCompilerPass to use PhpFileLoader instead of XmlFileLoader
• README: Updated routing reference from routing.xml to routing.yaml

XML configuration is deprecated in Symfony 7.4 and will be removed in Symfony 8.0.

2. Add PHP 8.5 and Symfony 8 support

• composer.json:
  • symfony/framework-bundle: ^6.4|^7.0|^8.0
  • All Symfony component dev dependencies: added ^8.0
  • doctrine/doctrine-migrations-bundle: ^2.0 || ^3.0 || ^4.0 (v4 for Symfony 8)
  • symfony/phpunit-bridge: ^7.3|^8.0
• CI: Added PHP 8.5 and Symfony 8.0.* to the test matrix
• CI exclusions: Symfony 8 requires PHP 8.4+, so PHP 8.1/8.2/8.3 are excluded when testing Symfony 8
• Test fixture: Added config_symfony8.yml for Symfony 8 tests

3. Add Docker setup for contributors

• Dockerfile: PHP 8.3 CLI with Composer and extensions
• docker-compose.yml: Service to run tests in a container
• Usage: docker compose run --rm php sh → then composer install && composer test

4. Documentation

• UPGRADE.md: Added notes for the routing file change (BC break for users who import routes manually)
• composer.json: Added scripts.test for composer test

Backward compatibility

• ✅ Symfony 6.4 and 7.x remain fully supported
• ✅ PHP 8.1–8.5 supported
• ⚠️ BC break: Users who import bundle routes with routing.xml must update to routing.yaml (see UPGRADE.md)

Testing

All 97 tests pass. Verified with:

docker compose run --rm php sh
# Inside container:
composer install
composer test

Related

• Symfony 7.4: Deprecated XML Configuration
• Symfony 8.0 release