[codex] Fix Symfony extension deprecation

[tacman]

Summary

• Replace the HttpKernel Extension base-class import with the DependencyInjection Extension import.
• Keeps the bundle extension API unchanged while avoiding the Symfony 8.1 internal/deprecated class warning.

Root cause

Symfony 8.1 considers Symfony\Component\HttpKernel\DependencyInjection\Extension internal/deprecated for bundle extensions. The public base class now lives at Symfony\Component\DependencyInjection\Extension\Extension.

Validation

• php -l src/DependencyInjection/AndanteTimestampableExtension.php
• vendor/bin/phpunit tests/Functional/DependencyInjection/DefaultConfigTest.php
• vendor/bin/phpstan analyse src/DependencyInjection/AndanteTimestampableExtension.php currently stops on existing phpstan.neon options: checkMissingIterableValueType and checkGenericClassInNonGenericObjectType

References #12

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[cristoforocervino]

Thanks @tacman !

[cristoforocervino]

@tacman the PR is still in draft. Is it done?

[tacman]

@tacman the PR is still in draft. Is it done?

Yep, I think it's all set!