* Update Shippable integration test groups.
* Update integration test group aliases.
* Rebalance AWS and Azure tests with extra group.
* Rebalance Windows tests with another group.
* If we evaluate task.loop/with_items when calculating delegate_to vars, cache the items. Fixes#28231
* Add comments about caching loop items
* Add test for delegate_to+loop+random
* Be more careful about where we update task.loop