Update deploy-book.yml to use upload-artifact v4

Author: liamjberrisford

.github/workflows/deploy-book.yml

@@ -39,11 +39,11 @@ jobs:
 
     # Upload the book's HTML as an artifact
     - name: Upload artifact
-      uses: actions/upload-pages-artifact@v2
+      uses: actions/upload-pages-artifact@v3
       with:
         path: "_build/html"
 
     # Deploy the book's HTML to GitHub Pages
     - name: Deploy to GitHub Pages
       id: deployment
-      uses: actions/deploy-pages@v2
+      uses: actions/deploy-pages@v4