fix: set up Node.js before pnpm/action-setup@v6

pnpm/action-setup@v6 requires Node.js to be installed beforehand.
Swapped the order: setup-node runs first, then pnpm/action-setup.

Author: jihchi

.github/workflows/main.yml

@@ -23,14 +23,13 @@ jobs:
       - name: Checkout repo
         uses: actions/checkout@v6
 
-      - uses: pnpm/action-setup@v6
-
       - name: Set-up Node.js ${{ matrix.node }}
         uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node }}
           check-latest: true
-          cache: pnpm
+
+      - uses: pnpm/action-setup@v6
 
       - name: Install dependencies
         run: pnpm install --frozen-lockfile