MyPy fails to check `TypedDict.update` call with only explicit keyword arguments

Bug Report

Calls to TypedDict.update don't type-check, even if all the updates are specified using keyword arguments.

To Reproduce

Type-check this program:

from typing import TypedDict

class Args(TypedDict, total=False):
    a: int
    b: str

args = Args()
args.update(a=123, b="abc")

Expected Behavior

The code should type-check, since all arguments to TypedDict.update were passed as keyword arguments, and the types of the arguments are correct.

Actual Behavior

$ mypy test.py
test.py:8: error: Unexpected keyword argument "a" for "update" of "TypedDict"  [call-arg]
/lib/python3.10/site-packages/mypy/typeshed/stdlib/typing.pyi:894: note: "update" of "TypedDict" defined here
test.py:8: error: Unexpected keyword argument "b" for "update" of "TypedDict"  [call-arg]
/lib/python3.10/site-packages/mypy/typeshed/stdlib/typing.pyi:894: note: "update" of "TypedDict" defined here
Found 2 errors in 1 file (checked 1 source file)

Your Environment

• Mypy version used: 1.9.0
• Mypy command-line flags: none (just ran mypy test.py)
• Mypy configuration options from mypy.ini (and other config files): none (no special configuration)
• Python version used: 3.10

Start with the provided Python reproducer and compare the reported signature in typeshed/stdlib/typing.pyi with how mypy handles TypedDict.update calls. Add regression coverage for keyword-only updates and verify that running mypy on the example reports no errors.