fix(pre-commit): don't try tagging *both* 3 and 4 as "latest"
When pre-commit 4 was added, the "latest" tag wasn't removed from pre-commit-3.3 meaning that which ended up as "latest" depended on which would be the most recent image built by CI.
When pre-commit 4 was added, the "latest" tag wasn't removed from pre-commit-3.3 meaning that which ended up as "latest" depended on which would be the most recent image built by CI.