The current condition being checked to decide when to prune after updating
a flatpak from the public API is probably not the best one, since NO_DEPLOY
doesn't imply that prunable objects will be available, as that's something
that depends on whether a pull operation is performed, not a deployment.
So, change that condition so that we now always prune after updating unless
a NO_PULL flag has been explicitly set, which means that no prunable objects
would be available and so it's safe to ignore that step.
https://github.com/flatpak/flatpak/issues/1703Closes: #1704
Approved by: alexlarsson