implement wgpuComputePassEncoderSetPushConstants

[zackgomez]

It was straightforward to implement. I don't expect my changes to the example to be merged, I am looking for guidance on whether they should be reverted, moved to another example, or something else entirely.

Test Plan:
Modified the compute shader to use push constants. Verified the output.

[rajveermalviya]

Let's keep the compute example as-is, but a separate example for push_constants would be great to have. Also seems like cargo fmt CI is not happy.

[almarklein]

cc @fyellin since you implemented render push constants in wgpu-py.

[zackgomez]

rebased and added examples/push_constants

Also noting that I used my fork of wgpu with these PRs in a project and they all worked as expected

[rajveermalviya]

Looks great so far! Added couple of comments.

We could also consider porting over this wgpu test so that we have a reference to track any future wgpu-core API changes and easily update the examples if needed.

[rajveermalviya]

Apart from the example, the API changes LGTM (and tests correctly with current example code). If you need we could merge the API changes in this PR, and do the example in a separate PR.

[fyellin]

When will this code be available to use in wgpu-py?

[almarklein]

When will this code be available to use in wgpu-py?

@fyellin when a new version of wgpu-native is released, and wgpu-py updates to that release.

[zackgomez]

pls merge

[rajveermalviya]

Thanks, Looks good!

(I also added a commit to run the example in CI)

[almarklein]

Thanks @zackgomez !