Fix bad migration.

drizzle/0039_add_ucl_bracket_simulator_type.sql

@@ -1 +1,9 @@
+DO $$ BEGIN
+  IF NOT EXISTS (
+    SELECT 1 FROM pg_enum
+    WHERE enumlabel = 'ucl_bracket'
+      AND enumtypid = (SELECT oid FROM pg_type WHERE typname = 'simulator_type')
+  ) THEN
     ALTER TYPE "public"."simulator_type" ADD VALUE 'ucl_bracket';
+  END IF;
+END $$;