Debug operations are not implemented for render bundles

The push/pop debug group and debug marker operations are [not implemented](https://github.com/gfx-rs/wgpu/blob/45e96e593fa8e3c9767de385c08899764018889e/wgpu-core/src/command/bundle.rs#L1840) for render bundles.

I have classified this as a bug because it is required WebGPU functionality, but it could also be considered an enhancement.