Cluster count missing from tenant api output

[jasonyates]

NetBox version

3.1.5

Python version

3.9

Steps to Reproduce

Assign a Cluster to a Tenant.
Retrieve Tenant details via API i.e. /api/tenancy/tenants/5/

Expected Behavior

cluster_count is returned as part of the API response

Observed Behavior

cluster_count is missing from the API response

[jeremystretch]

This is a bug. The field is declared on the serializer but its value is not being populated by the view.