fix: move SET LOCAL inside transaction in quotation/media/comms migration scripts

backend/migration/migrate_crm_comms_log.py

@@ -63,13 +63,12 @@ async def run() -> None:
         })
 
     async with AsyncPgSession() as session:
-        await session.execute(text("SET session_replication_role = replica"))
         async with session.begin():
+            await session.execute(text("SET LOCAL session_replication_role = replica"))
             stmt = pg_insert(CrmCommsLog).values(records)
             stmt = stmt.on_conflict_do_nothing(index_elements=["id"])
             await session.execute(stmt)
             dest_count = await pg_count(session, "crm_comms_log")
-        await session.execute(text("SET session_replication_role = DEFAULT"))
 
     if dest_count < source_count:
         msg = f"Count mismatch: source={source_count}  postgres={dest_count}"