build(deps-dev): Bump pnpm from 10.18 to 10.20 (#2804)

Author: KATO-Hiro

package.json

@@ -95,7 +95,7 @@
     "vercel": "48.8.2",
     "xss": "1.0.15"
   },
-  "packageManager": "pnpm@10.18.0",
+  "packageManager": "pnpm@10.20.0",
   "engines": {
     "node": ">=18.16.0"
   }