[naga]: Add no_std polyfill for round_ties_even for f32 and f64

[bushrat011899]

Connections

• Contributes to Support no_std where possible (specifically for wasm32v1-none) #6826

Description

• Generalizes the round_ties_even f16 polyfill for f32 and f64 using num_traits::float::FloatCore, specifically for no_std support
• Adds naga to the Check no_std CI action now that it is MVP compatible

Testing

• CI

Squash or Rebase?

Squash

Checklist

• Run cargo fmt.
• Run taplo format. N/A
• Run cargo clippy --tests. If applicable, add:
  • --target wasm32-unknown-unknown
• Run cargo xtask test to run tests.
• If this contains user-facing changes, add a CHANGELOG.md entry.

Notes

• I haven't added a feature to switch back to f32::round_ties_even or f64::round_ties_even, since I don't believe there is substantial value added with such a feature.
• I have not added tests for the implementation, since it is based on the existing f16 polyfill. However, there are substantial tests for this exact method in this num-traits PR I opened. This PR would just allow us to continue working on no_std support while we wait for that PR to be accepted (or not).