Re-add python image to ci matrix

Author: Robinlovelace

.github/ISSUES/000-revive-dockerhub-hosting.md

@@ -41,6 +41,8 @@ jobs:
             dockerfile: mamba-py/Dockerfile
           - image: mamba-pyr
             dockerfile: mamba-pyr/Dockerfile
+          - image: python
+            dockerfile: python/Dockerfile
           - image: pythonr
             dockerfile: pythonr/Dockerfile
           - image: latest # This is the root Dockerfile