Changelog (https://github.com/symfony/symfony/compare/v6.3.6...v6.3.7)

• bug #52329 [HttpClient] Psr18Client: parse HTTP Reason Phrase for Response (@Hanmac)
• bug #52332 [Yaml] Fix deprecated passing null to trim() (@javaDeveloperKid)
• bug #52343 [Intl] Update the ICU data to 74.1 (@jderusse)
• bug #52347 [Form] Fix merging form data and files (ter) (Jan Pintr)
• bug #52307 [Scheduler] Save checkpoint in a finally block (@FrancoisPog)
• bug #52308 [SecurityBundle] Fix missing login-link element in xsd schema (@fancyweb)
• bug #51992 [Serializer] Fix using DateIntervalNormalizer with union types (@Jeroeny)
• bug #52276 DB table locks on messenger_messages with many failures (@bn-jdcook)
• bug #52232 [Messenger] declare constructor argument as optional for backwards compatibility (@xabbuh)
• bug #52283 [Serializer] Handle default context when denormalizing timestamps in DateTimeNormalizer (@mtarld)
• bug #52268 [Mailer][Notifier] Update Sendinblue / Brevo API host (@Stephanie)
• bug #52255 [Form] Skip merging params & files if there are no files in the first place (@dmaicher, @priyadi)

[PR] https://github.com/symfony/symfony/pull/52357