Symfony 5.4.1 has just been released. Here is a list of the most
important changes:

bug #44490 [DependencyInjection][Messenger] Add auto-registration for BatchHandlerInterface (@GaryPEGEOT)
bug #44523 [Console] Fix polyfill-php73 requirement (@Seldaek)
bug #44502 [HttpFoundation] do not call preg_match() on null (@xabbuh)
bug #44475 [Console] Handle alias in completion script (@GromNaN)
bug #44481 [FrameworkBundle] Fix loginUser() causing deprecation (@wouterj)
bug #44416 [Translation] Make http requests synchronous when reading the Loco API (@Kocal)
bug #44437 [HttpKernel] Fix wrong usage of SessionUtils::popSessionCookie (@simonchrz)
bug #44350 [Translation] Fix TranslationTrait (@Tomasz Kusy)
bug #44460 [SecurityBundle] Fix ambiguous deprecation message on missing provider (@chalasr)
bug #44467 [Console] Fix parameter types for ProcessHelper::mustRun() (@derrabus)
bug #44427 [FrameworkBundle] Fix compatibility with symfony/security-core 6.x (deps=high tests) (@wouterj)
bug #44424 [SecurityBundle] Don’t rely on deprecated strategy constants (@derrabus)
bug #44399 Prevent infinite nesting of lazy ObjectManager instances when ObjectManager is reset (@Ocramius)
bug #44395 [HttpKernel] fix sending Vary: Accept-Language when appropriate (@nicolas-grekas)
bug #44385 [DependencyInjection] Skip parameter attribute configurators in AttributeAutoconfigurationPass if we can’t get the constructor reflector (@fancyweb)
bug #44359 Avoid duplicated session listener registration in tests (@alexander-schranz)
bug #44375 [DoctrineBridge] fix calling get_class on non-object (@kbond)
bug #44378 [HttpFoundation] fix SessionHandlerFactory using connections (@dmaicher)
bug #44365 [SecurityBundle] Fix invalid reference with always_authenticate_before_granting (@chalasr)
bug #44361 [HttpClient] Fix handling error info in MockResponse (@fancyweb)
bug #44370 [Lock] create lock table if it does not exist (@martinssipenko)

Want to upgrade to this new release? Because Symfony protects
backwards-compatibility very closely, this should be quite easy. Use
SymfonyInsight upgrade reports
to detect the code you will need to change in your project and
read our upgrade
documentation to learn more.

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