Caching bug with tags of images

[nigelgbanks]

There is a caching bug locally when building targeting the latest tag. I believe what is happening is locally a previous image exists for the same inputs, say when changing branches back and forth, but the tag isn't being update when changing back and forth between branches as the caching logic is only checking that the expected image exists not that it exists and has the expected tag latest. It should track the tags it produced on a previous build and force a rebuild if the current tags and image digests do not match.

[nigelgbanks]

As a work around you can use --rerun-tasks as an argument to force rebuilding of images and re-tagging of images when changing branches.

[nigelgbanks]

Fixed by pull