Remove Keyspace::QueuedJobs

[yahoNanJing]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

A job with only its job id and without its plan is useless.

Describe the solution you'd like

Therefore, it's better to remove the Keyspace::QueuedJobs. Then it will also reduce the IO cost.

Describe alternatives you've considered

Additional context