pushing of artifacts should be imperative when enabled during bst build
When running bst build and the user has the right to push things, artifacts which were successfully built but not pushed (because of ^C
interruption or aborting because of an orthogonal build failure, or for whatever reason the push failed last time around) are forgotten and never pushed unless explicitly pushed with bst push
.
This is weird and feels not symmetric with the rest of the build, instead since we already know what needs to be pushed, we should re-add locally cached artifacts which are not present in the remote to the scheduler so they can be pushed if they are not yet pushed.