When manually creating a benchmark, the field "Competition Docker Image" should contain `codalab/codalab-legacy:py37` by default: <img width="964" alt="Capture d’écran 2023-06-01 à 17 08 55" src="https://github.com/codalab/codabench/assets/11784999/038b109a-8979-446b-8aab-d2fc0f5a1afb">