Update actions/setup-node action to v4 (#3)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/site.yaml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-node@v3
+      - uses: actions/setup-node@v4
         with:
           node-version: 22.x
       - run: npm ci

.github/workflows/test.yaml

@@ -21,7 +21,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: with Node.js ${{ matrix.node-version }} on ${{ matrix.os }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm ci
@@ -32,7 +32,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-node@v3
+      - uses: actions/setup-node@v4
         with:
           node-version: 23.x
       - run: npm ci