NRF charm goes into blocked state on remove

[markbeierl]

Describe the bug

NRF charm does not always go away; it lingers with

nrf/0*    blocked     executing  10.1.69.107         Scaling is not implemented for this charm

To Reproduce

1. Deploy the sdcore bundle
2. Destroy the model (via juju or terraform)
3. Wait for all charms to be removed
4. Note if NRF is in blocked state

Expected behavior

Model should be deleted without user intervention

Screenshots

Model   Controller          Cloud/Region        Version  SLA          Timestamp  Notes
sdcore  microk8s-localhost  microk8s/localhost  3.1.7    unsupported  15:18:04Z  attempt 44 to destroy model failed (will retry):  model not empty, found 4 applications (model no
t empty)

App   Version  Status      Scale  Charm            Channel   Rev  Address         Exposed  Message
ausf           unknown         0  sdcore-ausf-k8s  1.3/edge   38  10.152.183.42   no            
nrf            blocked       1/0  sdcore-nrf-k8s   1.3/edge   40  10.152.183.44   no       Scaling is not implemented for this charm
udr            unknown         0  sdcore-udr-k8s   1.3/edge   32  10.152.183.119  no            
upf            terminated      0  sdcore-upf-k8s   1.3/edge   38  10.152.183.230  no            

Unit   Workload    Agent      Address      Ports  Message
nrf/0  blocked     executing  10.1.69.107         Scaling is not implemented for this charm
upf/0  terminated  executing  10.1.69.117         (remove) 

[dariofaccin]

Closing as probably this is fixed by #117