chore(deps): update pnpm to v8.15.6

Author: renovate[bot]

package.json

@@ -4,7 +4,7 @@
   "type": "module",
   "version": "2.2.6",
   "license": "MIT",
-  "packageManager": "[email protected].5",
+  "packageManager": "[email protected].6",
   "scripts": {
     "lc:new": "tsx ./src/cmd/leetcode.ts",
     "dev": "astro dev",