Update dart.yml

.github/workflows/dart.yml

@@ -24,7 +24,7 @@ jobs:
           git config --global user.name "j-j-gajjar"
           git status
           git remote -v
-          git remote add origin "https://${{secrets.commit_secret}}@github.com/j-j-gajjar/Mathematics.git"
+          git config remote.origin.url "https://j-j-gajjar:${{secrets.commit_secret}}@github.com/j-j-gajjar/Mathematics.git"
           git checkout -b gh-pages
           git add --all
           git commit -m "update"