Update GitHub Pages deploy action version

Author: nexus-uw

.github/workflows/ghpage.yml

@@ -31,7 +31,7 @@ jobs:
         -v ${{ github.workspace }}:/srv/jekyll -v ${{ github.workspace }}/_site:/srv/jekyll/_site \
         jekyll/builder:latest /bin/bash -c "chmod -R 777 /srv/jekyll && jekyll build --future"
     - name: Deploy to GitHub Pages
-      uses: JamesIves/github-pages-deploy-action@4
+      uses: JamesIves/github-pages-deploy-action@v4
       with:
           branch: gh-pages # The branch the action should deploy to.
           folder: _site # The folder the action should deploy.