Introduce `golangci` to Workhorse

Contributes to https://gitlab.com/gitlab-org/gitlab/-/issues/432836

`golangci` is a linter agregator that supports lots of linters:
https://golangci-lint.run/

* Add a new command to Makefile: `make golangci`.
* Provide an initial configuration for `.golangci.yml`

Changelog: other