Make unscheduled tasks section height configurable

[Ash-Shy]

Describe the bug
I can't find the option of "Unscheduled tasks height limit"

To Reproduce
Steps to reproduce the behavior:

1. open the setting，this is version 1.16
   

Expected behavior
Not being able to modify the height makes my usage space very limited, and opening the perimeter view also takes up a considerable amount of space.

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
nothing