ci: bump Pages workflow actions off deprecated Node 20

GitHub is deprecating the Node.js 20 runtime on Actions runners, and
checkout@v4, configure-pages@v5, and upload-pages-artifact@v3 (through its
bundled upload-artifact@v4) still target it. This bumps those three to
versions that run on Node 24. deploy-pages@v5 already runs on Node 24 and is
unchanged.

Signed-off-by: Jared Watts <jbw976@gmail.com>

Author: jbw976

.github/workflows/pages.yml

@@ -28,11 +28,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Setup Pages
-        uses: actions/configure-pages@v5
+        uses: actions/configure-pages@v6
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v3
+        uses: actions/upload-pages-artifact@v5
         with:
           # Publish only the site directory, not the repo's README or workflow.
           path: "./public"