chore(deps): update dependency tsdown to v0.20.0

Author: renovate[bot]

package.json

@@ -67,7 +67,7 @@
     "rollup": "4.55.1",
     "rollup-plugin-dts": "6.1.1",
     "ts-node": "10.9.2",
-    "tsdown": "0.18.4",
+    "tsdown": "0.20.0",
     "turbo": "2.7.5",
     "typescript": "5.9.3",
     "typescript-eslint": "8.29.1",