WebGPU support warning needs updating for Firefox

[mrec]

https://bevy.org/examples-webgpu/ (and all examples under it) still says

Support Warning

WebGPU is currently only supported on Chrome starting with version 113, and only on desktop. If they don't work on your configuration, you can check the WebGL2 examples here.

This is now out of date since Firefox also supports WebGPU on Windows as of 141 🎉🥳

Looks like just templates/example-webgpu.html and templates/examples-webgpu.html that need fixing.