Closes #21662: Increase rf_channel_frequency Precision (#21690)

Increase `rf_channel_frequency` precision from two to three decimal
places.

Update the field definition and migration to use `max_digits=8` and
`decimal_places=3`, preserving support for higher channel frequencies
while allowing more precise values to be stored.

netbox/dcim/migrations/0229_interface_rf_channel_frequency_precision.py

@@ -0,0 +1,23 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dcim', '0228_cable_bundle'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='interface',
+            name='rf_channel_frequency',
+            field=models.DecimalField(
+                blank=True,
+                decimal_places=3,
+                help_text='Populated by selected channel (if set)',
+                max_digits=8,
+                null=True,
+                verbose_name='channel frequency (MHz)',
+            ),
+        ),
+    ]

netbox/dcim/models/device_components.py

@@ -807,8 +807,8 @@ class Interface(
         verbose_name=_('wireless channel')
     )
     rf_channel_frequency = models.DecimalField(
-        max_digits=7,
-        decimal_places=2,
+        max_digits=8,
+        decimal_places=3,
         blank=True,
         null=True,
         verbose_name=_('channel frequency (MHz)'),