Fix type inference for QmlElement

from PySide6.QtCore import QObject
from PySide6.QtQml import QmlElement

@QmlElement
class Erased(QObject):
    pass

E = TypeVar("E")
def TypedQmlElement(arg: E) -> E:
    return QmlElement(arg)

@TypedQmlElement
class NotErased(QObject):
    pass

def do_something():
    return Erased(), NotErased()

erased, not_erased = do_something()
# Pylance shows "erased: Any, not_erased: NotErased"

E = TypeVar("E")
def QmlElement(arg__1: E) -> E: ... 
# or
def QmlElement(arg__1): ...