Implement `pre-upgrade-check` action (#168) #79

Job	Run time
configure-channel	1s
charmcraft-channel	3s
publish-to-edge (./charms/worker/, k8s-worker, arm64) / select-channel	4s
publish-to-edge (./charms/worker/, k8s-worker, amd64) / select-channel	2s
publish-to-edge (./charms/worker/k8s/, k8s, arm64) / select-channel	4s
publish-to-edge (./charms/worker/k8s/, k8s, amd64) / select-channel	3s
publish-to-edge (./charms/worker/, k8s-worker, amd64) / Publish charm to latest/edge	41s
publish-to-edge (./charms/worker/k8s/, k8s, amd64) / Publish charm to latest/edge	43s
publish-to-edge (./charms/worker/, k8s-worker, arm64) / Publish charm to latest/edge	38s
publish-to-edge (./charms/worker/k8s/, k8s, arm64) / Publish charm to latest/edge	39s
publish-to-edge (./charms/worker/, k8s-worker, arm64) / Draft publish docs	15s
publish-to-edge (./charms/worker/, k8s-worker, arm64) / Release charm libs	5s
publish-to-edge (./charms/worker/k8s/, k8s, arm64) / Release charm libs	39s
publish-to-edge (./charms/worker/k8s/, k8s, arm64) / Draft publish docs	18s
publish-to-edge (./charms/worker/, k8s-worker, amd64) / Draft publish docs	25s
publish-to-edge (./charms/worker/, k8s-worker, amd64) / Release charm libs	5s
publish-to-edge (./charms/worker/k8s/, k8s, amd64) / Release charm libs	37s
publish-to-edge (./charms/worker/k8s/, k8s, amd64) / Draft publish docs	18s
	5m 40s

Provide feedback