Update Dawn library

[sessamekesh]

Looks like another warning has snuck in - the WGSL language has changed again, and is replacing [[decoration]] style blocks with @decoration style annotations.

[sessamekesh]

Updated in c237db5

But... guess what? It's time to update again! This time the API for specifying load/store ops against framebuffers on render pass creation has changed.... so you need to update again 🙃

[sessamekesh]

Looks like part of the API has become deprecated: RenderPassEncoder EndPass method is now End.

This is not reflected in the Emscripten WebGPU bindings yet - https://github.com/emscripten-core/emscripten/blob/a02b254dfedce9c8a26b9bc3f9a11561f9adeb58/system/include/webgpu/webgpu_cpp.h#L893

This change is breaking in Chromium - https://source.chromium.org/chromium/chromium/src/+/main:out/Debug/gen/third_party/dawn/emscripten-bits/webgpu_cpp.h;l=935;drc=0366351bbd562c89684c861a1c8be1eb84e0f42e

This might be okay for now, but at some point the build will be broken.

Open an issue up with Emscripten to discuss possible resolution of the issue.

[sessamekesh]

Also (and this is really weird) - the master up-to-date Dawn build is not giving the same errors the Chromium build is giving - my guess is there's a flag in there somewhere.