PyQt6: QEvent.type() returns int instead of QEvent.Type

[Phil Thompson]

On the local PyPI server is an sdist for PyQt6-sip v13.4.0 which 
implements the support for missing enum members. The current PyQt6 
snapshot requires this version.

QEvent.type() now returns a QEvent.Type. I've left in the QEvent ctor 
that takes an int but it is deprecated.

Phil