Changelog (v6.4.20...v6.4.21)

• bug[VarExporter] dump default value for property hooks if present #60288 [VarExporter] dump default value for property hooks if present (@xabbuh)
• bug[Contracts] FixServiceSubscriberTrait for nullable service #60268 [Contracts] FixServiceSubscriberTrait for nullable service (@StevenRenaux)
• bug[Mailer][Postmark] drop theDate header using the API transport #60256 [Mailer][Postmark] drop theDate header using the API transport (@xabbuh)
• bug[VarExporter] Fix: Use correct closure call for property-specific logic in $notByRef #60258 [VarExporter] Fix: Use correct closure call for property-specific logic in $notByRef (@Hakayashii,@denjas)
• bug[Notifier] [Discord] Fix value limits #60269 [Notifier] [Discord] Fix value limits (@norkunas)
• bug[Messenger] Revert " Add call togc_collect_cycles() after each message is handled" #60248 [Messenger] Revert " Add call togc_collect_cycles() after each message is handled" (@jwage)
• bug[String] Support nexus -> nexuses pluralization #60236 [String] Support nexus -> nexuses pluralization (@KorvinSzanto)
• bug[Workflow] Fix dispatch of entered event when the subject is already in this marking #60194 [Workflow] Fix dispatch of entered event when the subject is already in this marking (@lyrixx)
• bug[Cache] Fix invalidating on save failures with Array|ApcuAdapter #60172 [Cache] Fix invalidating on save failures with Array|ApcuAdapter (@nicolas-grekas)
• bug[Cache] ArrayAdapter serialization exception clean $expiries #60122 [Cache] ArrayAdapter serialization exception clean $expiries (@bastien-wink)
• bug[Cache] Fix proxying third party PSR-6 cache items #60167 [Cache] Fix proxying third party PSR-6 cache items (Dmitry Danilson)
• bug[HttpKernel] Do not ignore enum in controller arguments when it has an#[Autowire] attribute #60165 [HttpKernel] Do not ignore enum in controller arguments when it has an#[Autowire] attribute (@ruudk)
• bug[Console] Correctly convertSIGSYS to its name #60168 [Console] Correctly convertSIGSYS to its name (@cs278)
• bug[Security] fix(security): fix OIDC user identifier #60166 [Security] fix(security): fix OIDC user identifier (@vincentchalamon)
• bug[Validator] : fix url validation when punycode is on tld but not on domain #60124 [Validator] : fix url validation when punycode is on tld but not on domain (@joelwurtz)
• bug[Mailer] FixTrying to access array offset on value of type null error by adding null checking #60057 [Mailer] FixTrying to access array offset on value of type null error by adding null checking (@khushaalan)
• bug[DoctrineBridge] Fix support for entities that leverage native lazy objects #60094 [DoctrineBridge] Fix support for entities that leverage native lazy objects (@nicolas-grekas)
• bug[DoctrineBridge] Fix support for entities that leverage native lazy objects #60094 [DoctrineBridge] Fix support for entities that leverage native lazy objects (@nicolas-grekas)