Remove unique constraint on chat room names

Fixes #763

I think the actual constraint we would want is unique names per server,
but this model doesn't have that info. As it is this caused problems
last year when puzzles had titles identical to previous year puzzles.

chat/migrations/0010_remove_chatroom_unique_room_name_per_service.py

@@ -0,0 +1,17 @@
+# Generated by Django 4.1.13 on 2024-12-15 08:23
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("chat", "0009_alter_chatrole_id_alter_chatroom_id"),
+    ]
+
+    operations = [
+        migrations.RemoveConstraint(
+            model_name="chatroom",
+            name="unique_room_name_per_service",
+        ),
+    ]

chat/models.py

@@ -55,13 +55,6 @@ class ChatRoom(models.Model):
     audio_channel_url = models.URLField(null=True, blank=True)
     audio_channel_id = models.CharField(max_length=255, null=True, blank=True)
 
-    class Meta:
-        constraints = [
-            models.UniqueConstraint(
-                name="unique_room_name_per_service", fields=["service", "name"]
-            ),
-        ]
-
     def __str__(self):
         return self.name