perf(scheduler): use deque for o(1) queue operations

[pathoam]

Change Type

• perf: Performance improvement.

Description

Replace list with collections.deque for the scheduler's wait queue. list.pop(0) is O(n) because it shifts all elements; deque.popleft() is O(1).

Key Changes

1. Changed _wait_queue type from List to Deque
2. Changed .pop(0) to .popleft() in admit_requests()
3. Updated imports accordingly

[pathoam]

lint was initially blocked because I put a space at the beginning of the pr title by accident. should work now

[yuhao-zh]

Thanks for your contribution，I will review your code shortly and then test its performance.
Merge will be soon.

[pathoam]

@yuhao-zh
following up on this, have you had a chance to review?