Merge pull request #147 from rust-lang/renovate/tsdown-0.x

chore(deps): update dependency tsdown to ^0.18.0

Author: renovate[bot]

package.json

@@ -28,7 +28,7 @@
         "globals": "^16.5.0",
         "msw": "^2.12.4",
         "prettier": "^3.7.4",
-        "tsdown": "^0.17.3",
+        "tsdown": "^0.18.0",
         "tslib": "^2.8.1",
         "typescript": "^5.9.3",
         "typescript-eslint": "^8.49.0",