CI: move actions to versions that run on Node 24

checkout/setup-node v4 run on the deprecated Node 20 runtime.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -13,8 +13,8 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v5
+      - uses: actions/setup-node@v5
         with:
           node-version: 22
           cache: npm
@@ -44,13 +44,13 @@ jobs:
     needs: test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v5
+      - uses: actions/setup-node@v5
         with:
           node-version: 22
       - name: Build site
         run: npm run build && npm run site
-      - uses: actions/upload-pages-artifact@v3
+      - uses: actions/upload-pages-artifact@v4
         with:
           path: _site