Remove old versionadded directives

Author: OskarStark

components/event_dispatcher.rst

@@ -262,14 +262,6 @@ determine which instance is passed.
     default values by passing custom values to the constructors of
     ``RegisterListenersPass`` and ``AddEventAliasesPass``.
 
-.. versionadded:: 4.3
-
-    Aliasing event names is possible since Symfony 4.3.
-
-.. versionadded:: 4.4
-
-    The ``AddEventAliasesPass`` class was introduced in Symfony 4.4.
-
 .. _event_dispatcher-closures-as-listeners:
 
 .. index::

event_dispatcher.rst

@@ -270,11 +270,6 @@ name (FQCN) of the corresponding event class::
         }
     }
 
-.. versionadded:: 4.3
-
-    Referring Symfony's core events via the FQCN of the event class is possible
-    since Symfony 4.3.
-
 Internally, the event FQCN are treated as aliases for the original event names.
 Since the mapping already happens when compiling the service container, event
 listeners and subscribers using FQCN instead of event names will appear under
@@ -303,10 +298,6 @@ The compiler pass will always extend the existing list of aliases. Because of
 that, it is safe to register multiple instances of the pass with different
 configurations.
 
-.. versionadded:: 4.4
-
-    The ``AddEventAliasesPass`` class was introduced in Symfony 4.4.
-
 Debugging Event Listeners
 -------------------------