fix: raft cluster has no leader error

[lilian-delouvy]

Issue and Steps to Reproduce

Slimfaas pods sometimes loop on an error "raft cluster has no leader". I don't know why yet, but I guess the following can occur:

• several slimfaas pods try to become leader at once
• several pods can't reach each other, which may prevent a leader from being elected

Fix

Deleting all the slimfaas pods and its statefulset, before restarting the kustomize and notification controllers, makes slimfaas restart properly.