QGIS Python module type stubs broken by empty enums and reserved name

[komima]

What is the bug or the crash?

QGIS Python module type stub .pyi files have errors, and types are not available in IDE/mypy/pyright contexts.

1. Empty enums are output from QgsProcessingContext and QgsModelComponentGraphicItem, and the syntax is not valid:
   

2. self is used as parameter name in QgsVectorDataProvider (and I assume in all subclasses if that is relevant, for example in QgsPostgresProvider), and that conflicts with the instance parameter in Python method signature:
   

Steps to reproduce the issue

• Use any python interpreter to create a new venv and install mypy
• Set PYTHONPATH env var to point at the installed qgis python module
• Use stubgen to generate stubs with stubgen -m qgis.core or stubgen -m qgis.gui
• Observe that previously shown errors occur when parsing existing .pyis

Versions

QGIS 3.22.0 on Windows 10 (from osgeo v2 network installer qgis-package)

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

• QGIS .pyis were added (at least to Windows packaging) based on Generate type stub files for python API #41264
• Unrelated to this specific bug (but contributing to missing types), PyQt5 .pyis are missing on Windows for now (ticket for that issue)
• Lots of enum changes happened lately?
• Update from 3.16/py3.7 to 3.22/py3.9 caused this issue to appear, previous stubs include the empty enums as they probably should appear as class Flag(int): .... Those were taken from docker image and are Generated by SIP 4.19.21, current install stubs are Generated by SIP 6.1.1, so SIP version might also be a relevant change.