chore: migrate to tsdown

Author: dreyfus92

package.json

@@ -10,7 +10,7 @@
     "type-check": "tsc --noEmit",
     "format": "prettier --write .",
     "format:check": "prettier --check .",
-    "build": "tsup",
+    "build": "tsdown",
     "prepare": "pnpm build",
     "lint": "eslint src \"./*.ts\""
   },
@@ -27,7 +27,7 @@
     "commander": "^13.1.0",
     "eslint-config-prettier": "^10.0.1",
     "prettier": "^3.5.2",
-    "tsup": "^8.3.6",
+    "tsdown": "^0.9.7",
     "tsx": "^4.19.1",
     "typescript": "^5.7.3",
     "typescript-eslint": "^8.25.0",