[Notifier] remove extra backtick character

Author: hhamon

notifier.rst

@@ -830,7 +830,7 @@ Using Events
     The ``MessageEvent``, ``FailedMessageEvent`` and ``SentMessageEvent`` were
     introduced in Symfony 5.4.
 
-The :class:`Symfony\\Component\\Notifier\\Transport`` class of the Notifier component
+The :class:`Symfony\\Component\\Notifier\\Transport` class of the Notifier component
 allows you to optionally hook into the lifecycle via events.
 
 The ``MessageEvent::class`` Event