Upgrade github deploy actions to V4

Author: Gareth Farrington

.github/workflows/static.yml

@@ -40,7 +40,7 @@ jobs:
         run: |
           npm run build
       - name: Upload Artifact
-        uses: actions/upload-pages-artifact@v2
+        uses: actions/upload-pages-artifact@v4
         with:
           # Upload contents of the build output directory:
           path: 'build/'
@@ -56,4 +56,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v2
+        uses: actions/deploy-pages@v4