fix(core): Use gettext_lazy in data.py

Replace `gettext()` with `gettext_lazy()` to avoid locale-dependent
model serialization (and false-positive pending migration warnings).
Also make a missing `ValidationError` message translatable and
format-safe.

Fixes #21175

netbox/core/models/data.py

@@ -12,7 +12,7 @@ from django.core.validators import RegexValidator
 from django.db import models
 from django.urls import reverse
 from django.utils import timezone
-from django.utils.translation import gettext as _
+from django.utils.translation import gettext_lazy as _
 
 from netbox.constants import CENSOR_TOKEN, CENSOR_TOKEN_CHANGED
 from netbox.models import PrimaryModel
@@ -128,7 +128,9 @@ class DataSource(JobsMixin, PrimaryModel):
         # Ensure URL scheme matches selected type
         if self.backend_class.is_local and self.url_scheme not in ('file', ''):
             raise ValidationError({
-                'source_url': "URLs for local sources must start with file:// (or specify no scheme)"
+                'source_url': _("URLs for local sources must start with {scheme} (or specify no scheme)").format(
+                    scheme='file://'
+                )
             })
 
     def save(self, *args, **kwargs):

netbox/translations/en/LC_MESSAGES/django.po

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2026-01-13 05:05+0000\n"
+"POT-Creation-Date: 2026-01-15 05:05+0000\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -12489,8 +12489,8 @@ msgstr ""
 msgid "Delete Selected"
 msgstr ""
 
-#: netbox/netbox/plugins/navigation.py:55
-#: netbox/netbox/plugins/navigation.py:88
+#: netbox/netbox/plugins/navigation.py:53
+#: netbox/netbox/plugins/navigation.py:89
 msgid "Permissions must be passed as a tuple or list."
 msgstr ""
 
@@ -12498,7 +12498,7 @@ msgstr ""
 msgid "Buttons must be passed as a tuple or list."
 msgstr ""
 
-#: netbox/netbox/plugins/navigation.py:92
+#: netbox/netbox/plugins/navigation.py:95
 msgid "Button color must be a choice within ButtonColorChoices."
 msgstr ""