Enable postgresql unaccent extension

resolwe/flow/migrations/0025_add_unaccent_extension.py

@@ -0,0 +1,13 @@
+# Generated by Django 4.2.9 on 2024-02-13 07:00
+
+from django.db import migrations
+from django.contrib.postgres.operations import UnaccentExtension
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("flow", "0024_update_sql_entity_methods"),
+    ]
+
+    operations = [UnaccentExtension()]