662: API and examples update for index_format r=kvark a=kejor __Connections__ #608 https://github.com/gfx-rs/wgpu/issues/978 https://github.com/gfx-rs/wgpu/pull/1019 __Description__ Use new API from 4513fb2b83 where `wgpu_render_pass_set_index_buffer` and `wgpu_render_bundle_set_index_buffer` receive an `index_format` and `VertexStateDescriptor`'s `index_format` is an `Option`. The examples were updated accordingly. Co-authored-by: kejor <kevinoviedorueda@gmail.com>
4513fb2b83