Update pnpm to v9.15.8

| datasource | package | from   | to     |
| ---------- | ------- | ------ | ------ |
| npm        | pnpm    | 9.12.0 | 9.15.8 |

Author: renovate[bot]

package.json

@@ -30,5 +30,5 @@
   "devDependencies": {
     "@types/node": "^22.7.4"
   },
-  "packageManager": "pnpm@9.12.0"
+  "packageManager": "pnpm@9.15.8"
 }