Disable Python 2 builds on mac

Since we plan to remove Python 2 support by the end of the year and there is already discussion to disable python 2 on mac: bob.nightlies#41 and https://gitlab.idiap.ch/beat/beat.backend.python/-/jobs/148622

I propose to disable Python 2 on Mac machines right away.

ping @samuel.gaist @andre.anjos

mentioned in issue beat/beat.backend.python#18 (closed)

mentioned in issue beat/beat.core#61 (closed)

mentioned in issue beat/beat.editor#157 (closed)

I hope you're making the right choice here. BTW, I think it would be a good idea to ping the (Bob) mailing list again with a reminder, so people can't complain when this happens.

I think is a good call to remove python2.7 on mac. To keep it in the long run I think we would need to have someone officially allocated to handle and find best solutions for the our runners that match all our needs.

Thanks for this patch @amohammadi

merged

mentioned in commit eaa97b9a