ci: add cargo-machete to Trunk

[zmalatrax]

We want to have Trunk as a unique source of truth for linters and formatters, including those who are not available out-of-the-box. (i.e. available through a plugin made by Trunk).

cargo-machete is not available in Trunk.
So it requires adding a custom linter to the CI (or potentially make a Trunk plugin in a separate repo to use it across various repo).

I first tried taking inspo from the clippy plugin without success (it wasn't a prio atm)