Improve workaround for wgpu's gles texture type inference

[teohhanhui]

• Remove unnecessary feature flag (atlas) from WebGL2 section

To be honest, I can't see any difference with or without the patch. Everything seems to work fine when running the examples through wasm-server-runner without --features atlas anyway... Has the workaround been added somewhere else? (I can't find anything...)

Closes #395
Closes #283

[rparrett]

I should test again, but as far as I remember, #395 is still valid -- it should be tested with atlases consisting of exactly 12 (or other multiples of 6 greater than 6) tiles. It's possible that this was only an issue for native GL. Also possible that something changed on the wgpu side and it's no longer an issue.

[teohhanhui]

You're right. This workaround is needed. I'm trying out bevy_ecs_tilemap and without this patch, I'm getting:

ERROR app:  wgpu-hal heuristics assumed that the view dimension will be equal to `D2` rather than `D2Array`.
`D2` textures with `depth_or_array_layers == 1` are assumed to have view dimension `D2`
`D2` textures with `depth_or_array_layers > 1` are assumed to have view dimension `D2Array`
`D2` textures with `depth_or_array_layers == 6` are assumed to have view dimension `Cube`
`D2` textures with `depth_or_array_layers > 6 && depth_or_array_layers % 6 == 0` are assumed to have view dimension `CubeArray` log.target = "wgpu_hal::gles";
log.module_path = "wgpu_hal::gles";
log.file = "/home/teohhanhui/.cargo/registry/src/index.crates.io-6f17d22bba15001f/wgpu-hal-0.21.1/src/gles/mod.rs";
log.line = 421;

Just as expected... (and of course the render is wrong too)

[teohhanhui]

/ping @rparrett Please let me know if there are any outstanding concerns.