CI/CD: only/except migration to rules - extend when to support schedules/not scheduled

Everyone can contribute. Help move this issue forward while earning points, leveling up and collecting rewards.

Problem to solve

As only/except are getting discouraged in favour of rules in GitLab 13 I noticed missing support for handling schedules condition.

Proposal

I think extending when with schedules option would be the easiest way to solve lack of this functionality for rules.

Edited by 🤖 GitLab Bot 🤖