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

* #17725: Resolve all F401 errors

* Tweak noqa designation

netbox/vpn/api/serializers_/crypto.py

@@ -1,5 +1,3 @@
-from rest_framework import serializers
-
 from netbox.api.fields import ChoiceField, SerializedPKRelatedField
 from netbox.api.serializers import NetBoxModelSerializer
 from vpn.choices import *

netbox/vpn/apps.py

@@ -7,7 +7,7 @@ class VPNConfig(AppConfig):
 
     def ready(self):
         from netbox.models.features import register_models
-        from . import search
+        from . import search  # noqa: F401
 
         # Register models
         register_models(*self.get_models())