Compactor becomes unhealthy in the ring when stopped during startup #6533

Describe the bug
Compactor becomes unhealthy in the ring if it is stopped while still starting.

To Reproduce
Steps to reproduce the behavior:

1. Scale up the number of compactors by 1
2. Once the compactor reads Running (0/1), scale back down the number of compactors

Expected behavior
Compactor gets removed from the ring.

Environment:

• Infrastructure: Kubernetes