Move decoder interface def into rolling stock

ram/metadata/migrations/0008_remove_decoder_interface.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.1.2 on 2022-10-31 23:01
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("metadata", "0007_rename_track_scale_tracks"),
+        ("roster", "0013_rollingstock_decoder_interface"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="decoder",
+            name="interface",
+        ),
+    ]