Attempt #2: build the doc in every PR< but do the deploy step only af…

…ter merged

.github/workflows/gh-pages-deploy.yml

@@ -15,7 +15,6 @@ jobs:
         contents: write
         pull-requests: write
         pages: write
-        repository-projects: write
 
 
     steps:
@@ -30,6 +29,7 @@ jobs:
       run: doxygen Doxyfile
 
     - name: Deploy to GitHub Pages
+      if: github.event_name == 'push' && github.ref == 'refs/heads/main'
       uses: peaceiris/actions-gh-pages@v3
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}