We only want to use the session if the request is **not** `stateless`. The old code used the sesison only in `stateless` requests (so requests not intended to use the session (=state) at all).

* 6.4:
  fix merge
  [AssetMapper] Split test dirs in tests
  Fix typo
  Change incorrect check for the `stateless` request attribute
  use copy() instead of rename() on Windows
  test: kebab-case to snake_case
  [PropertyInfo] Handle collection in PhpStan same as PhpDoc
  [Messenger] Passing to `WorkerMessageRetriedEvent` envelope with actual stamps after sent

* 6.4:
  [Console][PhpUnitBridge][VarDumper] Fix `NO_COLOR` empty value handling
  [Translation] Fix CSV escape char in `CsvFileLoader` on PHP >= 7.4
  [DoctrineBridge] fix messenger bus dispatch inside an active transaction
  [HttpFoundation] Add tests for uncovered sections
  treat uninitialized properties referenced by property paths as null
  properly set up constraint options
  [ErrorHandler][VarDumper] Remove PHP 8.4 deprecations
  [Profiler] Add word wrap in tables in dialog to see all the text
  [Core] Fix & Enhance security arabic translation.