Bump actions/deploy-pages from 2 to 4 (#37)

Bump actions/deploy-pages from 2 to 4

Author: Guts

.github/workflows/documentation.yml

@@ -83,4 +83,4 @@ jobs:
       - name: Deploy to GitHub Pages
         id: deployment
         if: ${{ github.event_name == 'push' && ( startsWith(github.ref, 'refs/tags/') || github.ref == 'refs/heads/main' ) }}
-        uses: actions/deploy-pages@v2
+        uses: actions/deploy-pages@v4