Put back open in colab markers
# What does this PR do?

This PR should be merged once everything is ready on moon-landing (cc @mishig25 I will wait for your green light).
Making a note that this PR should be merged after https://github.com/huggingface/moon-landing/pull/1621 gets merged<|||||>@sgugger done on the moon-landing side. Please feel free to merge this PR<|||||>Thanks!