Bump the cosign version (a lot) (#1839)
Bump the cosign version (a lot) (#1839)

The cosign version being used was ancient.  This catches us up to 1.4.1 (latest).

I was also eyeballing the very redundant jobs in `release.yaml` for a subsequent refactoring to make this a matrix job, so there are a couple of trivial cleanups related to this.
GoogleContainerTools/kaniko,GoogleContainerTools/kaniko,GoogleContainerTools/kaniko