chore(deps): Update actions/setup-node action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: pnpm/action-setup@v3
         with:
           version: 8
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 20.x
           cache: pnpm
@@ -36,7 +36,7 @@ jobs:
         with:
           version: 8
       - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node-version }}
           cache: pnpm
@@ -62,7 +62,7 @@ jobs:
         with:
           version: "2"
       - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node-version }}
           cache: pnpm