Issue #3338328 by Spokje, andypost, longwave, effulgentsia, jungle, catch, smustgrave, Wim Leers: Update to Symfony 6.3

Issue #3233031 by daffie, longwave, murilohp: [Symfony 6] Add "RequestContext" type hint to methods overridding Symfony\Component\Routing\RequestContextAwareInterface::getContext()

Issue #3233041 by daffie: [Symfony 6] Add "array" type hint to methods overridding Symfony\Component\Routing\Matcher\UrlMatcherInterface::match()

Issue #3232895 by daffie: [Symfony 6] Add "string" type hint to methods overridding Symfony\Component\Routing\Generator\UrlGeneratorInterface::generate()

Issue #3233045 by daffie, longwave: [Symfony 6] Add "array" type hint to methods overridding Symfony\Component\Routing\Matcher\RequestMatcherInterface::matchRequest()

Issue #3233023 by daffie: [Symfony 6] Add "RouteCollection" type hint to methods overridding Symfony\Component\Routing\RouterInterface::getRouteCollection()

Issue #3209619 by longwave, daffie, catch: [Symfony 6] Passing null as $message to Symfony exception constructors is deprecated, pass an empty string instead

Issue #2869426 by Wim Leers, dawehner, tstoeckler, alexpott, Berdir, larowlan: EntityResource should add _entity_access requirement to REST routes

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

Issue #2810303 by dawehner, Crell, tim.plunkett, klausi, Wim Leers: Reunite the router: One router to rule them all

Revert "Issue #2810303 by dawehner, Crell, klausi, tim.plunkett, Wim Leers: Reunite the router: One router to rule them all"

This reverts commit 21a86f3a.

Issue #2810303 by dawehner, Crell, klausi, tim.plunkett, Wim Leers: Reunite the router: One router to rule them all

Issue #2681911 by garphy, Wim Leers, gabesullice: REST requests without X-CSRF-Token header: unhelpful response significantly hinders DX, should receive a 401 response

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #1392754 by tss, justAChris, jhodgdon: Comply with new documentation standards for @file for namespaced class files

Issue #2458349 by Wim Leers: Route's access result's cacheability not applied to the response's cacheability

Issue #2286971 by znerol, Berdir, almaudoh, cilefen: Remove dependency of current_user on request and authentication manager

Issue #2288911 by znerol, effulgentsia: Use route name instead of system path in user maintenance mode subscriber

Issue #2340251 by iMiksu, alexpott, tim.plunkett, dawehner, Wim Leers: Remove most remaining url() calls.

Issue #2331079 by znerol, dawehner: Use RouteMatch in access-checks and remove RequestHelper::duplicate().

Issue #2322809 by chx, dawehner, tim.plunkett: Tighten routing security by access checking in matchRequest.