wx paint demo (and thus probably wxDC) does not work with Wayland

[rongcuid]

Describe the bug
When using GDK_BACKEND=wayland, wx paint does not update properly.

To Reproduce

1. Run erl
2. wx:demo()
3. Go to paint example, try to paint
4. Canvas does not update unless something is done to the window, such as resizing
5. Run GDK_BACKEND=x11 erl
6. Try again, this time paint works

Expected behavior
Wayland and X11 backend should behave the same

Affected versions
26.2.1

Additional context
My system: Gentoo Linux with wxGTK-3.2.5 and erlang-26.2.1, running Plasma 6 on Wayland with NVIDIA driver

I tried some wxDC samples directly with C++, and those work. So it's probably something wrong in OTP

[rongcuid]

I did, however, find this note in Gentoo's wxGTK build:

    # By default, we now build with the GLX GLCanvas because some software like
    # PrusaSlicer does not yet support EGL:
    #
    # https://github.com/prusa3d/PrusaSlicer/issues/9774 .
    #    
    # A solution for this is being developed upstream:
    #
    # https://github.com/wxWidgets/wxWidgets/issues/22325 .
    #
    # Any software that needs to use OpenGL under Wayland can be patched like
    # this to run under xwayland:
    #
    # https://github.com/visualboyadvance-m/visualboyadvance-m/commit/aca206a721265366728222d025fec30ee500de82 .
    #
    # Check that the macro wxUSE_GLCANVAS_EGL is set to 1.
    #
    myeconfargs+=( "--disable-glcanvasegl" )

That is, my wxWidgets would not be able to build with EGL.