Move typing_extensions to stdlib (#5233)

I'm not sure what the best way to do this is. This effectively orphans
types-typing-extensions, but maybe that's not really a problem. (We can
yank the package too)

See https://github.com/python/typeshed/pull/5229#issuecomment-822234125
for some details

Co-authored-by: hauntsaninja <>

stubs/waitress/METADATA.toml

@@ -1,2 +1,2 @@
 version = "0.1"
-requires = ["types-typing-extensions"]
+requires = []