Add a Makefile target to cleanly execute linter locally

[Taepper]

Local linting should be executable (after fulfilling clearly defined requirements) by just invoking make lint. The CI should also use this command from within the dependency image (which will satisfy the requirements in its build-step)

[Taepper]

It should NOT rerun the linter on all files, if only a single file has changed. If afterwards still running through docker, this could be achieved through file mounts instead of COPY . ./ in the Dockerfile