trying to switch gh-pages deployment action to https://github.com/gr2m/ghpages-1

in order to try out whether this pull request works for me:
maxheld83/ghpages#18

Author: fiedl

.github/workflows/build.yml

@@ -27,7 +27,7 @@ jobs:
         mkdir public
         cp latex-beamer/build/*.pdf public/
     - name: GitHub Pages Deploy
-      uses: maxheld83/ghpages@v0.2.1
+      uses: gr2m/ghpages-1@v0.2.1
       env:
         BUILD_DIR: public/
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}