ci: fix doc build

Author: jll63

.github/workflows/ci.yml

@@ -122,5 +122,5 @@ jobs:
           path: doc/build/site
 
       - name: Deploy to GitHub Pages
-        if: github.repository_owner == 'jll63' && github.ref_name == 'feature/doc'
+        if: matrix.os == 'ubuntu-latest' && github.repository_owner == 'jll63' && github.ref_name == 'feature/doc'
         uses: actions/deploy-pages@v4