This PR was squashed before being merged into the 4.3 branch (closes#33828).
Discussion
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[DoctrineBridge] Auto-validation must work if no regex are passed
| Q | A
| ------------- | ---
| Branch? | 4.3
| Bug fix? | yes
| New feature? | no <!-- please update src/**/CHANGELOG.md files -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tickets | n/a
| License | MIT
| Doc PR | n/a
Backport of https://github.com/symfony/symfony/pull/32107/files#r295762928.
This behavior if faulty, if no regex are passed, autvalidation must be triggered, [as done in `PropertyInfoLoader`](https://github.com/symfony/symfony/blob/4.3/src/Symfony/Component/Validator/Mapping/Loader/PropertyInfoLoader.php#L50).
Commits
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5ed7d6c759 [DoctrineBridge] Auto-validation must work if no regex are passed
ee4b99f227