Support doctrine 4

[larowlan]

Drupal 12 require symfony 8
Symfony 8 requires doctrine 4+

Additional high-level changes in this PR:

• Migrated CI from CircleCI to GitHub Actions, running inside the Skpr PHP CLI container.
• Bumped GitHub Actions to latest (checkout/upload-artifact v7); switched PHPUnit reporting to a --teamcity problem matcher and PHPCS to checkstyle + cs2pr for inline annotations.
• Raised minimum PHP to 8.2.
• Bumped dev dependencies to latest: coder 9, php_codesniffer 4, phpstan 2, phpunit 11.
• Removed abandoned pear/console_table and phpcompatibility/php-compatibility; added cs2pr.
• Stopped tracking composer.lock and added it to .gitignore (library convention).
• Migrated phpunit.xml.dist to the PHPUnit 11 schema and @group annotation to a #[Group] attribute.
• Removed redundant always-true asserts flagged by PHPStan and applied coding-standard fixes.

[kimpepper]

Reviewed the new GitHub Actions workflow.

• PHP provisioning: We don't usually use shivammathur/setup-php. Suggested running the job inside the standard Skpr PHP CLI container (skpr/php-cli:<version>-dev-v2-latest), which ships Composer and git.
• Action versions:actions/checkout@v4 and actions/upload-artifact@v4 are ~3 majors behind; bumped to the latest (v7).
• Composer:--no-suggest was removed in Composer 2.

Note: -latest image tags float the PHP patch version, which is fine for CI and consistent with other Skpr projects.

[kimpepper]

Follow-up to the previous review: instead of emitting a JUnit XML artifact, use a PHPUnit problem matcher so test failures surface inline as annotations. This supersedes the earlier upload-artifact@v7 suggestion.