gh-154727: List TLSv1.3 among SSLSocket.version() return values

Author: mimi89999

Doc/library/ssl.rst

@@ -1412,7 +1412,7 @@ SSL sockets also have the following additional methods and attributes:
    Return the actual SSL protocol version negotiated by the connection
    as a string, or ``None`` if no secure connection is established.
    As of this writing, possible return values include ``"SSLv2"``,
-   ``"SSLv3"``, ``"TLSv1"``, ``"TLSv1.1"`` and ``"TLSv1.2"``.
+   ``"SSLv3"``, ``"TLSv1"``, ``"TLSv1.1"``, ``"TLSv1.2"`` and ``"TLSv1.3"``.
    Recent OpenSSL versions may define more return values.
 
    .. versionadded:: 3.5