Remove `volumes = ["/cache"` from shared runners configuration
We still have volumes = ["/cache"]
configured for our autoscaled Runners (a leftover from the past). It's usable for Runner's that have MaxBuilds
set to more than 1 (so docker-ci-X, and all shared runners prepared for GitLab CE/EE projects). But for the regular shared runners, which have MaxBuilds = 1
this is not usable and may confuse users: support-forum#1689.
@ayufan what do you think?