Support doctrine/persistence ^3

[StephenBeirlaen]

Q	A
Bug fix?	no
New feature?	no
BC breaks?	no
Deprecations?	no
Fixed tickets	/
Related issues/PRs	/
License	MIT

What's in this PR?

To run Sulu with this bundle on Symfony 6.4, one of the constrained packages was doctrine/persistence, which was still locked to ^2 here, while ^3 is required.

I went through the upgrade notes on https://github.com/doctrine/persistence/blob/3.4.x/UPGRADE.md. This bundle does not seem to be affected by any BC breaking changes.

Note: Linting errors do not seem to be caused by this PR.

Why?

Move towards supporting Symfony 6.4

BC Breaks/Deprecations

There should be none.

[alexander-schranz]

@StephenBeirlaen Thank you!