I also deleted a test that would be entirely useless without capture clauses.

Deprecate util/dev in favor of cargo alias

This means one less shell script and a bit more cross-platform support
for contributors.

If you've been using `./util/dev` before, this now becomes `cargo dev`.

The key part of this change is found in `.cargo/config` where an alias for calling the `clippy_dev` binary is defined.

changelog: none