Create from code should be restricted to public repositories

[leafty]

See also: SwissDataScienceCenter/renku#4064

It seems that the UI for "Create from code" has been updated to allow any repository with pull permission to be used for "Create from code" while the build system only allows public repositories to be used.

[lorenzo-cavazzi]

I think we did not update the "Create from code" section to distinguish between public and private repos. We never had that in place, but the private repos were not accessible.

Let's update the UI as soon as we get the information from the backend -- see SwissDataScienceCenter/renku-data-services#1213

[leafty]

This WAS in place, @lorenzo-cavazzi. The "probe" endpoint was dedicated to giving information about repositories without authentication and this is what was used for the repository selection.

In this way, only public repositories were allowed to be selected for "create from code".