While OpenGL ES 3.0 and WebGL 2.0 both support non power-of-2 (NPOT)
textures in their specification, the situation seems to be less clear
about *compressed* NPOT textures using repeat or mipmap flags.
At least Chrome on Linux doesn't seem to support this combination,
and a variety of mobile hardware have similar limitations.
As a workaround, we force decompressing such textures when running on
WebGL 2.0, at the cost of loading time and memory usage.
Fixes#33058.