"Arguments for ParamSpec are missing" error

**Describe the bug** Please have a look at python/typeshed#15597. In this PR, I try to change `operator.methodcaller` to use a `ParamSpec` with defaults: ```python _P = ParamSpec("_P", default=...) _R = TypeVar("_R", default=Any) @final class methodcaller(Generic[_P, _R]): def __new__(cls, name: str, /, *args: _P.args, **kwargs: _P.kwargs) -> methodcaller[_P, Any]: ... def __call__(self, obj: Any) -> _R: ... ``` Unfortunately, the following test cases then fail: ```python m1 = methodcaller("foo") # Arguments for ParamSpec "_P@methodcaller" are missing (reportCallIssue) assert_type(m1, methodcaller[[], Any]) # "assert_type" mismatch: expected "methodcaller[(), Any]" but received "methodcaller[..., Any]" m2 = methodcaller("foo", 42, bar="") # Arguments for ParamSpec "_P@methodcaller" are missing (reportCallIssue) ``` I'm unsure what there problem here seems to be. From the CI environment: pyright 1.1.408, node v24.14.0, pyright-action 3.0.2