- in Firefox, scrollbar would appear => adding overflow: hidden fixes this issue
- when the canvas has the focus, Chrome draws a very small blue outline, setting it to none fixes this issue
- This commit removes the option of using -sUSE_WEBGPU=1 from CMake and make
- Compiling with a version of Emscripten >= 4.0.10 will work the same way as it was before
- Compiling with a version of Emscripten < 4.0.10 will print an error message and abort the build (in the case of CMake)
- Since there can only be 1 implementation for the backend in the case of Emscripten, this commit cleans the code accordingly
