[Ballista] Wait based on available task slots #805
Description
Is your feature request related to a problem or challenge? Please describe what you are trying to do.
We can improve efficiency by avoiding polling and reducing sleep time.
Describe the solution you'd like
Wait some time until we have tasks available based on available_tasks_slots.
Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.
Additional context
Add any other context or screenshots about the feature request here.