Background:

We had two lint configs: lint-config.edn which was enfored by Github Actions, and
.clj-kondo/config.edn, the default location used by editors.


Problem:

Patchy enforcement of the (larger) config in .clj-kondo/config.edn since not
everyone uses an editor.

Some new lint, like canonical namespace aliases (#21738, #19930) is not enforced
automatically and has begun to bit-rot.

Solution:

Combine both configs, fix any outstanding lint, and update our tooling to use
the unified config.

Caveats:

Anyone who has their local editor configured to use lint-config.edn will have
their linting broken by this change.