dev/ci/integration: unify docker cleanup
Created by: bobheadxi
follow-up to https://github.com/sourcegraph/sourcegraph/pull/29429 , minor tweak to keep the old behaviour of doing a broader cleanup after each run
Created by: bobheadxi
follow-up to https://github.com/sourcegraph/sourcegraph/pull/29429 , minor tweak to keep the old behaviour of doing a broader cleanup after each run