UPGRADE FROM 5.0 to 5.1
=======================
EventDispatcher
---------------
* Deprecated `LegacyEventDispatcherProxy`. Use the event dispatcher without the proxy.
FrameworkBundle
* Deprecated passing a `RouteCollectionBuiler` to `MicroKernelTrait::configureRoutes()`, type-hint `RoutingConfigurator` instead
* Deprecated *not* setting the "framework.router.utf8" configuration option as it will default to `true` in Symfony 6.0
HttpFoundation
--------------
* Deprecate `Response::create()`, `JsonResponse::create()`,
`RedirectResponse::create()`, and `StreamedResponse::create()` methods (use
`__construct()` instead)
Routing
-------
* Deprecated `RouteCollectionBuilder` in favor of `RoutingConfigurator`.