PySide6.QtCore.SIGNAL is confused about its signature

Despite PYSIDE-782 is long closed, the issue is still with us in PySide6.

In QtCore.pyi, instead of

def SIGNAL(arg__1: bytes) -> str: ...
def SLOT(arg__1: bytes) -> str: ...

it should be

def SIGNAL(arg__1: str) -> str: ...
def SLOT(arg__1: str) -> str: ...

And I'd appreciate a better name for arg__1.