Check for attachment overlap using textures, not views

[andyleiserson]

Overlap of color attachments should be computed based on the actual texture resources, not the views used to reference them.

Fixes failure of the CTS test webgpu:api,validation,resource_usages,texture,in_pass_encoder:subresources_and_binding_types_combination_for_color:compute=false;type0="render-target";type1="render-target".

Partially addresses #3126.

Testing
Enables relevant CTS test.

Squash or Rebase? Squash

Checklist

• Run cargo fmt.
• Run taplo format.
• Run cargo clippy --tests. If applicable, add:
  • --target wasm32-unknown-unknown
• Run cargo xtask test to run tests.
• Added a CHANGELOG.md entry.

[teoxoy]

Makes sense.