fix(extras): Remove redundant post_save handler for ScriptModule

Remove signal-based sync_classes call that duplicated the direct call
already present in ScriptModule.save(). The explicit invocation in
save() is sufficient and eliminates unnecessary signal overhead.

Fixes #21869

netbox/extras/models/scripts.py

@@ -5,8 +5,6 @@ from functools import cached_property
 from django.contrib.contenttypes.fields import GenericRelation
 from django.db import models
 from django.db.models import Q
-from django.db.models.signals import post_save
-from django.dispatch import receiver
 from django.urls import reverse
 from django.utils.translation import gettext_lazy as _
 
@@ -189,8 +187,3 @@ class ScriptModule(PythonModuleMixin, JobsMixin, ManagedFile):
         self.file_root = ManagedFileRootPathChoices.SCRIPTS
         super().save(*args, **kwargs)
         self.sync_classes()
-
-
-@receiver(post_save, sender=ScriptModule)
-def script_module_post_save_handler(instance, created, **kwargs):
-    instance.sync_classes()