change workflow to use default rust action

[alejandro-vaz]

the default rust action workflow is easier to implement and maintain than our current CI workflow

we'd be replacing main.yml for rust.yml

the concrete CI tests should be the same ones

[Nidhi-Gahlawat]

Hi, I’d like to work on this. I’ll migrate the current CI checks from main.yml to the standard rust.yml workflow structure while preserving the existing build, test, documentation and benchmark.