Sync typeshed

[sobolevn]

To contunue my work on #11206 I need this typeshed commit: python/typeshed@4ac969a

Source commit:
python/typeshed@ca983cd

[github-actions]

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

python-chess (https://github.com/niklasf/python-chess.git)
+ chess/engine.py:1438: error: Argument 1 to "ChainMap" has incompatible type "Mapping[str, Union[str, int, bool, None]]"; expected "MutableMapping[str, Union[str, int, None]]"
+ chess/engine.py:1460: error: Argument 1 to "ChainMap" has incompatible type "Mapping[str, Union[str, int, bool, None]]"; expected "MutableMapping[str, Union[str, int, None]]"
+ chess/engine.py:2351: error: Argument 1 to "ChainMap" has incompatible type "Mapping[str, Union[str, int, bool, None]]"; expected "MutableMapping[str, Union[str, int, None]]"

aioredis (https://github.com/aio-libs/aioredis.git)
- aioredis/client.py:4650: error: Argument 1 to "sha1" has incompatible type "Union[bytes, str, memoryview]"; expected "Union[bytes, bytearray, memoryview, array[Any], mmap]"
+ aioredis/client.py:4650: error: Argument 1 to "sha1" has incompatible type "Union[bytes, str, memoryview]"; expected "Union[bytes, Union[bytearray, memoryview, array[Any], mmap, _CData]]"

sphinx (https://github.com/sphinx-doc/sphinx.git)
- sphinx/util/inspect.py:818:27: error: Incompatible types in assignment (expression has type "DefaultValue", variable has type "_empty")
+ sphinx/util/inspect.py:818:27: error: Incompatible types in assignment (expression has type "DefaultValue", variable has type "Type[_empty]")
- sphinx/util/inspect.py:828:23: 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 "Type[_empty]")

pandas (https://github.com/pandas-dev/pandas.git)
+ pandas/compat/chainmap.py:21: error: Redundant cast to "MutableMapping[_KT, _VT]"  [redundant-cast]
+ pandas/compat/chainmap.py:25: error: Redundant cast to "MutableMapping[_KT, _VT]"  [redundant-cast]
+ pandas/compat/chainmap.py:35: error: Redundant cast to "MutableMapping[_KT, _VT]"  [redundant-cast]
+ pandas/core/computation/scope.py:241: error: unused "type: ignore" comment

poetry (https://github.com/python-poetry/poetry.git)
- poetry/plugins/plugin_manager.py:22: error: Need type annotation for "_plugins" (hint: "_plugins: List[<type>] = ...")
+ poetry/mixology/failure.py:144: error: Item "DependencyCause" of "Union[RootCause, NoVersionsCause, DependencyCause, ConflictCause, PythonCause, PlatformCause, PackageNotFoundCause]" has no attribute "conflict"

edgedb (https://github.com/edgedb/edgedb.git)
+ edb/schema/delta.py:1225:38: error: Argument 1 to "ChainMap" has incompatible type "*List[Mapping[Optional[str], str]]"; expected "MutableMapping[Optional[str], str]"