Symfony7 next steps

[herbertroth]

This pull request includes minor dependency and configuration updates to improve compatibility and clean up the configuration.

Dependency updates:

• Expanded the supported versions of the symfony/runtime package in composer.json to include ^7.3, increasing compatibility with newer Symfony releases.

Configuration cleanup:

• Removed the enable_authenticator_manager: true line from config/packages/security.yaml, simplifying the security configuration.