Should a node be removed at least its prometheus/monitoring entry in the mine should be removed.
Given a node pi-k8s-01 run the following command to remove all mine entries.
salt-run mine.update 'pi-k8s-01' clear=True
The previous command only works while the minion is still connected to the master. If the minion is already removed you can execute this command.
salt-run cache.clear_all pi-k8s-01