Rollup merge of #107048 - DebugSteven:newer-x-check-cargo, r=albertlarsan68

Rollup merge of #107048 - DebugSteven:newer-x-check-cargo, r=albertlarsan68

check for x version updates

This PR adds a check to tidy to assert that the installed version of `x` is equal to the version in `src/tools/x/Cargo.toml`. It checks the installed version of `x` by parsing the output of `cargo install --list` (as an option proposed in this [issue](https://github.com/rust-lang/rust/issues/106469)).

It does not warn if `x` has not yet been installed, on the assumption that the user isn't interested in using it.