Sync typeshed

[hauntsaninja]

Source commit:
python/typeshed@a9227ed

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

pip (https://github.com/pypa/pip.git)
+ src/pip/_internal/commands/debug.py:50: error: unused "type: ignore" comment

sphinx (https://github.com/sphinx-doc/sphinx.git)
+ sphinx/util/inspect.py:686: error: unused "type: ignore" comment
+ sphinx/util/inspect.py: note: In function "signature_from_ast":
+ sphinx/util/inspect.py:818:27: error: Incompatible types in assignment (expression has type "DefaultValue", variable has type "_empty")
+ sphinx/util/inspect.py:828:23: error: Incompatible types in assignment (expression has type "DefaultValue", variable has type "_empty")

aioredis (https://github.com/aio-libs/aioredis.git)
- aioredis/client.py:3401: error: Incompatible types in assignment (expression has type "KeysView[Any]", variable has type "Union[Sequence[Union[bytes, str, memoryview]], Mapping[bytes, float]]")
+ aioredis/client.py:3401: error: Incompatible types in assignment (expression has type "_dict_keys[Any, Any]", variable has type "Union[Sequence[Union[bytes, str, memoryview]], Mapping[bytes, float]]")
- aioredis/client.py:3401: error: Incompatible types in assignment (expression has type "KeysView[Any]", variable has type "Union[Sequence[Union[bytes, str, memoryview]], Mapping[str, float]]")
+ aioredis/client.py:3401: error: Incompatible types in assignment (expression has type "_dict_keys[Any, Any]", variable has type "Union[Sequence[Union[bytes, str, memoryview]], Mapping[str, float]]")
- aioredis/client.py:3401: error: Incompatible types in assignment (expression has type "KeysView[Any]", variable has type "Union[Sequence[Union[bytes, str, memoryview]], Mapping[memoryview, float]]")
+ aioredis/client.py:3401: error: Incompatible types in assignment (expression has type "_dict_keys[Any, Any]", variable has type "Union[Sequence[Union[bytes, str, memoryview]], Mapping[memoryview, float]]")

pytest (https://github.com/pytest-dev/pytest.git)
+ src/_pytest/main.py:481: note:     def __init__(self, iterable: Iterable[List[str]]) -> _bestrelpath_cache
- testing/test_pastebin.py:101: error: Argument 4 to "HTTPError" has incompatible type "Dict[<nothing>, <nothing>]"; expected "Message"  [arg-type]
+ testing/test_pastebin.py:101: note: (Skipping most remaining errors due to unresolved imports or missing stubs; fix these first)
- testing/test_config.py:422: note: (Skipping most remaining errors due to unresolved imports or missing stubs; fix these first)