We removed the wait_for_simulator_boot input from the step and introduced the headless_mode input instead.
With headless mode enabled the step will not force the simulator to boot in the foreground. Instead, xcodebuild will run the tests in the background.
Migration Guide
Moving from v1 to v2:
The v1.x version of the step will always force start the simulator and with default configuration the step will wait for a fixed 40 seconds for the simulator boot.
The v2.x version of the step will run in headless mode by default and will not start the simulator. Instead, xcodebuild will run the tests in the background.
In headless mode the simulator will not be visible but the tests will run in the same way (even the screenshots will be captured).
If you want to see the test run you can force start the simulator by disabling the headless_mode input. In this case the step will boot the simulator and it will wait for the simulator to boot.