The wx canvas hangs on CI with (the now default) bitmap present

[almarklein]

For context see pyapp-kit/scenex#42 (comment).

cc @gselzer

Windows-only, I believe.

[almarklein]

Looked into this (see almarklein/scenex#2). Some thing I found:

• The hang does not happen when using screen present.
• The hang does not happen when setting rendercanvas.utils.asyncs.USE_THREADED_TIMER = False.
• The hang is not caused by the overloading of Destroy().
• The hang does not happen locally.
• The hang is consistent on CI.

This looks like some kind of race condition (bitmap drawing is slower, CI (and drawing on it) is slower, thread involved ...). But I've not found the cause yet. My suspicion is that the canvas does not close, so the event loop hangs, but I might be wrong.

I think a good step now would be to try and reproduce the hanging in our https://github.com/pygfx/rendercanvas/blob/main/tests/test_gui_wx.py (which runs on ci).