Skip setting initialized readonly properties during refresh (#9505)

[YoussefMansour9]

Fixes #9505

Problem

$em->refresh($entity) crashes with LogicException when entity has readonly properties typed as objects (e.g., DateTimeImmutable). During hydration, ReadonlyAccessor::setValue() compares old and new values by identity (!==). Different PHP object instances of the same logical value trigger the comparison and throw.

Fix

In UnitOfWork::createEntity(), skip calling setValue() for fields whose accessor is ReadonlyAccessor and whose property is already initialized on the entity during refresh.

Testing

• All 1591 functional tests pass (0 failures)
• All 40 UnitOfWork unit tests pass
• All 7 Readonly functional tests pass

[greg0ire]

Testing

• All 1591 functional tests pass (0 failures)
• All 40 UnitOfWork unit tests pass
• All 7 Readonly functional tests pass

That's cool and all, but you should still add a test that would fail without your patch.

[greg0ire]

🤔 if you just skip the initialization, and the date has been changed by another process, refresh just won't work, leading to bugs.