Fix the versionadded for asyncio.StreamWriter.start_tls() (GH-92378)

(cherry picked from commit 063e8ab)

Co-authored-by: Oleg Iarygin <oleg@arhadthedev.net>

Author: miss-islington

Doc/library/asyncio-stream.rst

@@ -311,7 +311,7 @@ StreamWriter
         handshake to complete before aborting the connection.  ``60.0`` seconds
         if ``None`` (default).
 
-      .. versionadded:: 3.8
+      .. versionadded:: 3.11
 
    .. method:: is_closing()