Add missing versionadded. #12213

Author: OskarStark

components/process.rst

@@ -102,6 +102,11 @@ with a non-zero code)::
     :method:`Symfony\\Component\\Process\\Process::getLastOutputTime` method.
     This method returns ``null`` if the process wasn't started!
 
+    .. versionadded:: 4.4
+
+        The :method:`Symfony\\Component\\Process\\Process::getLastOutputTime`
+        method was introduced in Symfony 4.4.
+
 Using Features From the OS Shell
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