Changelog (https://github.com/symfony/symfony/compare/v6.4.8...v6.4.9)

• bug #57553 [HttpKernel] Enable optional cache-warmers when cache-dir != build-dir (@nicolas-grekas)
• bug #57497 [String] Fixed u()->snake(), b()->snake() and s()->snake() methods (@arczinosek)
• bug #57574 [Filesystem] Fix Filesystem::remove() on Windows (@nicolas-grekas)
• bug #57572 [DoctrineBridge] Fix compat with DI >= 6.4 (@nicolas-grekas)
• bug #57538 [String] Add alias case to EnglishInflector (@alexandre-daubois)
• bug #57533 [FrameworkBundle] Throw runtime exception when trying to use asset-mapper while http-client is disabled (@nicolas-grekas)
• bug #57520 [SecurityBundle] Remove unused memory users’ name attribute from the XSD (@MatTheCat)
• feature #57557 Ibexa is sponsoring Symfony 5.4, thanks to them! \o/ (@nicolas-grekas)
• bug #57569 [HttpClient][Mailer] Revert "Let curl handle transfer encoding", use HTTP/1.1 for Mailgun (@nicolas-grekas)
• bug #57499 [Mailer] Add additional headers in Scaleway bridge (@MrMicky-FR)
• bug #57460 [VarExporter] fix contravariance problem with __unserialize() in lazy proxy (@nikophil)
• bug #57397 [VarDumper] Fix FFI caster test (@alexandre-daubois)
• bug #57453 [HttpClient] Fix parsing SSE (@fancyweb)
• bug #57467 [SecurityBundle] Add provider XML attribute to the authenticators it’s missing from (@MatTheCat)
• bug #57384 [Notifier] Fix thread key in GoogleChat bridge (@romain-jacquart)
• bug #57372 [HttpKernel][Security] Fix accessing session for stateless request (@VincentLanglet)
• bug #57112 [Messenger] Handle AMQPConnectionException when publishing a message (@jwage)
• bug #57341 [Serializer] properly handle invalid data for false/true types (@xabbuh)
• bug #57187 [Serializer] Fix ObjectNormalizer with property path (@HypeMC)
• bug #57355 [ErrorHandler] Fix rendered exception code highlighting on PHP 8.3 (@tscni)
• bug #57310 [DependencyInjection] Fix ternary in AutowireCallable attribute (@alamirault)
• bug #57273 [FrameworkBundle] Fix setting default context for certain normalizers (@HypeMC)
• bug #57395 [Notifier]  send the recipient phone number as an array (@xabbuh)
• bug #52699 [Serializer] [PropertyAccessor] Ignore non-collection interface generics (@mtarld)
• bug #54634 [String] Fix #54611 pluralization of -on ending words + singularization of -a ending foreign words (@Geordie, @DesLynx)
• bug #57213 [Validator] [UniqueValidator] Use correct variable as parameter in (custom) error message (@seho-nl, Sebastien Hoek)
• bug #54920 [Messenger] Comply with Amazon SQS requirements for message body (@VincentLanglet)
• bug #57321 [AssetMapper] fix npm version constraint conversion (@Jean-Beru)
• bug #57110 [PhpUnitBridge] Fix error handler triggered outside of tests (@HypeMC)
• bug #57297 [FrameworkBundle] not registered definitions must not be modified (@xabbuh)
• bug #57234 [String] Fix Inflector for 'hardware' (@podhy)
• bug #57224 [Mime] Use streams instead of loading raw message generator into memory (@bytestream)

[PR] https://github.com/symfony/symfony/pull/57580