chore(deps): update dependency tsdown to ^0.15.5

Author: renovate[bot]

package.json

@@ -136,7 +136,7 @@
     "simple-git-hooks": "^2.13.1",
     "svelte": "^5.38.10",
     "svelte-eslint-parser": "^1.3.2",
-    "tsdown": "^0.14.2",
+    "tsdown": "^0.15.5",
     "typescript": "^5.9.2"
   },
   "pnpm": {