Changes to FlowManager.async_show_progress

FlowHandler.async_show_progress has been updated:

• The step_id parameter is deprecated and will be removed in Home Assistant core release 2024.8
• A new argument progress_task has been added, which will be mandatory in Home Assistant core release 2024.8

If progress_task is passed, FlowManager will:

• Send an event to fronted once the task has finished
• Cancel the progress_task if the user closes the config flow dialog before the task is done

This means derived classes are no longer responsible for interaction between the progress task state and the UI.

FlowHandler.async_show_progress will log a warning if it's called without a progress_task. In Home Assistant core release 2024.8, the call will instead fail.

More details can be found in the documentation and in core PR #107668 and "107802.