IBX-8470: Upgraded codebase to Symfony 6

[alongosz]

Caution

This is a part of bigger set of changes, to be merged together when ready

• ❗ Remove TMP commits before merge ❗

🎫 Issue	IBX-8470

Related PRs:

• IBX-8470: Upgraded codebase to Symfony 6 core#447
• IBX-8470: Bumped Symfony to version 6 doctrine-schema#27
• IBX-8470: Upgraded codebase to Symfony 6 behat#125
• IBX-8470: Upgraded codebase to Symfony 6 notifications#12
• IBX-8470: Upgraded codebase to Symfony 6 http-cache#54
• IBX-8470: Upgraded codebase to Symfony 6 rest#138
• IBX-8470: Upgraded codebase to Symfony 6 test-core#13

Description:

This PR bumps Symfony to v6 with necessary and optional codebase upgrades.

We had here a cyclic dependency on ibexa/user package. The deprecated Ibexa User extension points code was removed together with the dependency itself.

Key changes:

• [Composer] Dropped ci-scripts from dev requirements
• Bumped Symfony packages requirements to ^6.4
• Dropped deprecated Ibexa User Bundle extension points
• [Composer] Bumped jms/translation-bundle ^2.4 for Symfony 6 support
• [Composer] Dropped obsolete dependency on ibexa/user
• [Tests] Aligned form mapper tests with Symfony 6
• Added strict types to Symfony Bundle extension points methods
• Improved Symfony Bundle extension points code quality
• Refactored Legacy naming for Ibexa Core extension
• [Doc] Dropped obsolete doc directory

QA:

Sanities in the form of regression tests.

Documentation:

Dropped deprecated:

• Ibexa\ContentForms\User\View\UserRegisterConfirmView in favor of Ibexa\User\View\UserRegisterConfirmView
• Ibexa\ContentForms\User\View\UserRegisterFormView in favor for Ibexa\User\View\UserRegisterFormView
• Ibexa\Bundle\ContentForms\Controller\UserRegisterController in favor of \Ibexa\Bundle\User\Controller\UserRegisterController

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud