chore(deps): update dependency tsdown to ^0.20.0

Author: renovate[bot]

package.json

@@ -358,7 +358,7 @@
     "ovsx": "^0.10.7",
     "reactive-vscode": "^1.0.0-beta.2",
     "taze": "^19.9.2",
-    "tsdown": "^0.19.0-beta.3",
+    "tsdown": "^0.20.0",
     "typescript": "^5.9.3",
     "vite": "^7.3.0",
     "vitest": "^4.0.16",