Remove individual rust clippy and test jobs

[benluelo]

Given how our codebase has grown, it no longer makes sense to run clippy on each individual package. We should instead have one check that runs cargo clippy --workspace -- -D warnings (and similar for tests).

Steps

• Remove the checks attribute here
• Create two new checks in crane.nix (as siblings of packages.rust-coverage): checks.cargo-clippy and checks.cargo-test.
• checks.cargo-clippy: a crane.lib.cargoClippy derivation that passes --locked --workspace -- -D warnings as cargoExtraArgs
• checks.cargo-tests: a crane.lib.cargoTest derivation that passes --locked --workspace as cargoExtraArgs
• Both of these derivations will use cargoWorkspaceSrc as it's src.

Start with the clippy merge first, we will need to evaluate whether the tests are worth merging into one derivation.

Resources

The crane docs are quite thorough: https://crane.dev/; feel free to ping me if you have any questions!

[PoisonPhang]

One advantage to keeping these separate is with the new CI workflow from #1218, we'd only re-evaluate clippy and test for outputs who's nar hash has changed. I may be mistaken though, if any workspace member triggers a change in the nar hash, then my point it mute.

[benluelo]

Yeah I was thinking about that as well, but another benefit we get from doing this is clippy gets run on the entire repo without having to specify an output for every lib/bin/etc.