PEP 705: Remove extra self parameter from example (#3934)

Author: lancelote

peps/pep-0705.rst

@@ -353,7 +353,7 @@ Keyword argument typing
     class Function(Protocol):
         def __call__(self, **kwargs: Unpack[Args]) -> None: ...
 
-    def impl(self, **kwargs: Unpack[ReadOnlyArgs]) -> None:
+    def impl(**kwargs: Unpack[ReadOnlyArgs]) -> None:
         kwargs["key1"] = 3  # Type check error: key1 is readonly
 
     fn: Function = impl  # Accepted by type checker: function signatures are identical