Bump peaceiris/actions-gh-pages from 4.0.0 to 4.1.0 (#114)

Author: dependabot[bot]

.github/workflows/build.yml

@@ -46,7 +46,7 @@ jobs:
       - name: Push to fatiando.github.io
         if: success() && github.event_name == 'push'
         # Don't use tags: https://julienrenaux.fr/2019/12/20/github-actions-security-risk/
-        uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e
+        uses: peaceiris/actions-gh-pages@84c30a85c19949d7eee79c4ff27748b70285e453
         with:
           deploy_key: ${{ secrets.ACTIONS_DEPLOY_KEY }}
           external_repository: fatiando/fatiando.github.io