Update API domain

Author: cpsievert

.github/workflows/R-CMD-check.yaml

@@ -44,6 +44,7 @@ jobs:
       MAPBOX_TOKEN: ${{ secrets.MAPBOX_TOKEN }}
       plotly_username: ${{ secrets.PLOTLY_USERNAME }}
       plotly_api_key: ${{ secrets.PLOTLY_API_KEY }}
+      plotly_api_domain: "https://chart-studio.plotly.com"
 
     steps:
       - uses: actions/checkout@v4