Closes #17725: Clean up import statements (#17728)

* #17725: Resolve all F401 errors

* Tweak noqa designation

netbox/virtualization/api/serializers_/clusters.py

@@ -1,5 +1,3 @@
-from rest_framework import serializers
-
 from dcim.api.serializers_.sites import SiteSerializer
 from netbox.api.fields import ChoiceField, RelatedObjectCountField
 from netbox.api.serializers import NetBoxModelSerializer

netbox/virtualization/apps.py

@@ -9,7 +9,7 @@ class VirtualizationConfig(AppConfig):
     def ready(self):
         from netbox.models.features import register_models
         from utilities.counters import connect_counters
-        from . import search, signals
+        from . import search, signals  # noqa: F401
         from .models import VirtualMachine
 
         # Register models