`active_set_soft_limit` in MinTso scheduler does not work as expected.

[windtalker]

Bug Report

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1. Minimal reproduce step (Required)

active_set_soft_limit is expected to limit the active query count even if thread_soft_limit is not reached.
For example, if active_set_soft_limit is set to 10, and currently, the there is 10 running queries, then any new comming query should not be scheduled except that the new comming query is a query with min_tso.
But in current implementation:

tiflash/dbms/src/Flash/Mpp/MinTSOScheduler.cpp

Line 193 in 4ecf3cd

auto check_for_not_min_tso = (active_set.size() < active_set_soft_limit || query_id <= *active_set.rbegin()) && (estimated_thread_usage + needed_threads <= thread_soft_limit);

Even if active_set_soft_limit is already reached, the schedule will still allow new task to running if the tso of current task is less than the max_tso in current active set(active_set.size() < active_set_soft_limit || query_id <= *active_set.rbegin()).

2. What did you expect to see? (Required)

3. What did you see instead (Required)

4. What is your TiFlash version? (Required)