fix: rollback tsdown version for now

See #116

Author: Julien-R44

package.json

@@ -89,7 +89,7 @@
     "reflect-metadata": "^0.2.2",
     "release-it": "^19.2.4",
     "supertest": "^7.2.2",
-    "tsdown": "^0.21.4",
+    "tsdown": "0.20.3",
     "typedoc": "^0.28.17",
     "typescript": "^5.9.3",
     "youch": "^4.1.0"