improve list of browsers supporting WebGPU

for a followup PR: this is no longer true, WebGPU also works on some mobile browsers, and on Safari TP, and Firefox Nightly
We should probably link to something like https://caniuse.com/webgpu for a list or https://browserleaks.com/webgpu so that user can test their browser instead of keeping a list ourselves

_Originally posted by @mockersf in https://github.com/bevyengine/bevy-website/pull/1918#discussion_r1933004084_

No file or test is named. Find the website page that lists browsers supporting WebGPU, then review the linked caniuse.com/webgpu and browserleaks.com/webgpu resources; done means the outdated list is replaced or updated with a useful current link and accurately reflects mobile browsers, Safari Technology Preview, and Firefox Nightly.

Written by the indexing model from the issue text.