Bug 1831143 - use new mozillareleases/gecko_decision:4.1.0 docker image. r=releng-reviewers,bhearsum

Also bumping the cache version, because mercurial 6.1 enabled
share-safe, and robustcheckout in the old image doesn't understand that,
so upon encountering a repo cloned with the new version it would delete
everything and re-clone from scratch.

Differential Revision: https://phabricator.services.mozilla.com/D186543