[6.x] Bootstrap 5 compatibility for form block rendering

[Agbokoudjo]

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Description

This PR introduces Bootstrap 5 compatibility for rendering form blocks used by SonataBlockBundle.

It relies on a customized version of the sonata-project/form-extensions bundle, which includes the necessary updates for:

• Full Bootstrap 5 support in Twig templates
• Modernized JavaScript (using @eonasdan/tempus-dominus, Stimulus, etc.)
• Asset compilation using Webpack Encore
• Cleanup of deprecated dependencies

Changes Made

• Created the feature/bootstrap5-block-bundle branch
• Updated composer.json dependencies to point to the customized form-extensions branch
• Reviewed and validated all Twig templates (no changes needed at this stage)
• Built and integrated updated JS assets from the form-extensions bundle

Context

Sonata is still using Bootstrap 3 and AdminLTE v2 in several of its bundles.
This PR is a step toward the full migration to Bootstrap 5 and AdminLTE 4, while maintaining compatibility with Symfony 6.4 / 7.x.

Notes

This PR depends on the following form-extensions fork:

https://github.com/Agbokoudjo/form-extensions/tree/feature/bootstrap5-form-fields

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