Even easier Immediates

[Vipitis]

Checklist

• cargo clippy reports no issues
• [?] cargo doc reports no issues
• cargo deny issues have been fixed or added to deny.toml
• Human-readable change descriptions added to CHANGELOG.md under the "Unreleased" heading.
  • If the change does not affect the user (or is a process change), preface the change with "Internal:"
  • Add credit to yourself for each change: Added new functionality. @githubname

Description

While doing the v29 update for the python wrapper. I spotted that the descriptor already has a immediateSize field in webgpu.h webgpu-native/webgpu-headers#529
Also saw the limits being simplified in #575 so this makes it even simpler, although you still need the native only feature. I updated the example and it still works, please let me know if the changes to the wgpu.h headers are fine like this.

Related Issues

[lisyarus]

Nice! I think the changelog diff is a bit incorrect: it marks as released in v29 everything currently marked as unreleased, which isn't the case (there were new additions after v29). Apparently the current changelog in trunk contains both pre-v29 and post-v29 changes. Maybe just add your changes to unreleased for now, and then a separate PR would sort out the changelog itself?
@cwfitzgerald

[Vipitis]

yeah, I quickly looked at the blame and all your recentt changes should probably move to the top as well. I just tried to have mine a little more correct for now. I can add a commit to move yours tomorrow, or maybe do it outside this PR?

[lisyarus]

I'd suggest fixing the changelog in a separate PR, just to keep the history clean?

[Vipitis]

as this enum is removed, do all the others need to move up?