fix(ci): use pnpm instead of npm for Pages workflow

Author: Leftium

.github/workflows/pages.yml

@@ -23,12 +23,14 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v4
         with:
           node-version: 22
-          cache: npm
+          cache: pnpm
 
-      - run: npm ci
+      - run: pnpm install --frozen-lockfile
 
       - run: node build.js