Make runit recipes Rubocop friendly

• Run rubocop over existing runit directory
• Add runit directory to rubocop inspection list during CI jobs

@marin I tested the package for upgrade. Also I did disable and re-enabled a service (prometheus_monitoring, which did all exporters). It worked fine.

/cc @gitlab-build-team A spare pair of eyes would be great.

assigned to @marin

changed milestone to %9.3

approved this merge request

Looks ok to me :)

merged

mentioned in commit 3170317e