ObjectCountsWidget can brick Netbox home page

[candlerb]

Deployment Type

Self-hosted

NetBox Version

v4.0.10

Python Version

3.12

Steps to Reproduce

1. Go to home page
2. Click on settings cog next to an Object Counts widget
3. Add "DCIM > Console Server Port Template" to the list of objects to count, and click Save

Expected Behavior

Netbox continues to function, or the change is rejected.

Observed Behavior

Netbox web UI crashes and is unusable. There is no way to recover from the web UI.

This is because there is a hard-coded assumption in the widget that all models have a foo_list endpoint, but template components don't.

Originally raised in discussion #17336