[3.14] pythongh-134664: document cleanup_socket parameter in asyncio.start_unix_server (pythonGH-134750) (python#134779)

pythongh-134664: document `cleanup_socket` parameter in `asyncio.start_unix_server` (pythonGH-134750)
(cherry picked from commit 92ea1eb)

Co-authored-by: Shamil <ashm.tech@proton.me>

Author: miss-islington

Doc/library/asyncio-stream.rst

@@ -171,13 +171,17 @@ and work with streams:
 .. function:: start_unix_server(client_connected_cb, path=None, \
                  *, limit=None, sock=None, backlog=100, ssl=None, \
                  ssl_handshake_timeout=None, \
-                 ssl_shutdown_timeout=None, start_serving=True)
+                 ssl_shutdown_timeout=None, start_serving=True, cleanup_socket=True)
    :async:
 
    Start a Unix socket server.
 
    Similar to :func:`start_server` but works with Unix sockets.
 
+   If *cleanup_socket* is true then the Unix socket will automatically
+   be removed from the filesystem when the server is closed, unless the
+   socket has been replaced after the server has been created.
+
    See also the documentation of :meth:`loop.create_unix_server`.
 
    .. note::
@@ -198,6 +202,9 @@ and work with streams:
    .. versionchanged:: 3.11
       Added the *ssl_shutdown_timeout* parameter.
 
+   .. versionchanged:: 3.13
+      Added the *cleanup_socket* parameter.
+
 
 StreamReader
 ============