The mod/assign/tests/behat/set_availability.feature feature has a number of issues which are making it slow, buggy, and cumbersome:

• most of the steps do not require JS
• it uses the UI to set an admin setting, for every scenario:
  • only 3-4 of the scenarios actually test that setting
  • it is very slow to do it his way when we have a generator step we can use
• we create two assignments in the Background, but each test only uses one of them
• we create the assignments in the Background with a generator, but update them to modify various settings in each Scenario using the UI when we should just create one assignment for each test and set it up correctly for that Scenario