Update wgpu to 0.19.3

[Wumpf]

What

WebGPU APIs are now vendored inside of wgpu, meaning the only reason we still need unstable web-sys is clipboard support in egui.

Changelog 0.19.3
Changelog 0.19.2

Checklist

• I have read and agree to Contributor Guide and the Code of Conduct
• I've included a screenshot or gif (if applicable)
• I have tested the web demo (if applicable):
  • Using newly built examples: app.rerun.io
  • Using examples from latest main build: app.rerun.io
  • Using full set of examples from nightly build: app.rerun.io
• The PR title and labels are set such as to maximize their usefulness for the next release's CHANGELOG
• If applicable, add a new check to the release checklist!

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