fix(dcim): Handle missing Virtual Circuit Termination gracefully

Replace direct attribute access with try-except to catch
ObjectDoesNotExist when virtual_circuit_termination relation is missing.
Prevents errors when rendering Virtual Circuits Panel with broken or
missing terminations.

Fixes #21808

netbox/dcim/ui/panels.py

@@ -1,4 +1,5 @@
 from django.contrib.contenttypes.models import ContentType
+from django.core.exceptions import ObjectDoesNotExist
 from django.template.loader import render_to_string
 from django.utils.translation import gettext_lazy as _
 
@@ -532,8 +533,14 @@ class VirtualCircuitPanel(panels.ObjectPanel):
 
     def render(self, context):
         obj = context.get('object')
-        if not obj or not obj.is_virtual or not obj.virtual_circuit_termination:
+        if not obj or not obj.is_virtual:
             return ''
+
+        try:
+            obj.virtual_circuit_termination
+        except ObjectDoesNotExist:
+            return ''
+
         ctx = self.get_context(context)
         return render_to_string(self.template_name, ctx, request=ctx.get('request'))