Reset search promotions sequence after copying table content

We insert values manually, including an explicit pk, but don't ensure the sequence is set to a value higher than the largest pk.

See also https://code.djangoproject.com/ticket/17415

wagtail/contrib/search_promotions/migrations/0004_copy_queries.py

@@ -1,6 +1,18 @@
 # Generated by Django 3.1.8 on 2021-06-22 14:56
 
 from django.db import migrations
+from django.core.management.color import no_style
+
+
+def reset_search_promotion_sequence(apps, schema_editor):
+    Query = apps.get_model("wagtailsearchpromotions.Query")
+    QueryDailyHits = apps.get_model("wagtailsearchpromotions.QueryDailyHits")
+
+    statements = schema_editor.connection.ops.sequence_reset_sql(
+        no_style(), [Query, QueryDailyHits]
+    )
+    for statement in statements:
+        schema_editor.execute(statement)
 
 
 class Migration(migrations.Migration):
@@ -27,4 +39,9 @@ class Migration(migrations.Migration):
             """,
             "",
         ),
+        # We set an explicit pk instead of relying on auto-incrementation,
+        # so we need to reset the database sequence.
+        migrations.RunPython(
+            reset_search_promotion_sequence, migrations.RunPython.noop
+        ),
     ]