Upgrade to hierarkey 2.0 (#5373)

* Upgrade to hierarkey 2.0

* Fix duplicate setting of timezone

* Rebase migration

src/pretix/base/migrations/0286_settingsstore_unique.py

@@ -0,0 +1,28 @@
+# Generated by Django 4.2.16 on 2025-08-14 09:40
+
+from django.db import migrations
+from hierarkey.utils import CleanHierarkeyDuplicates
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("pretixbase", "0285_voucher_created"),
+    ]
+
+    operations = [
+        CleanHierarkeyDuplicates("GlobalSettingsObject_SettingsStore"),
+        CleanHierarkeyDuplicates("Organizer_SettingsStore"),
+        CleanHierarkeyDuplicates("Event_SettingsStore"),
+        migrations.AlterUniqueTogether(
+            name="event_settingsstore",
+            unique_together={("object", "key")},
+        ),
+        migrations.AlterUniqueTogether(
+            name="globalsettingsobject_settingsstore",
+            unique_together={("key",)},
+        ),
+        migrations.AlterUniqueTogether(
+            name="organizer_settingsstore",
+            unique_together={("object", "key")},
+        ),
+    ]