fix: Prevent simultaneous balance of segments and channels (#37850)

[weiliu1031]

issue: #33550
pr: #37850
balance segment and balance segment execute at same time, which will cause bounch of corner case.

This PR disable simultaneous balance of segments and channels

[codecov]

Codecov Report

Attention: Patch coverage is 77.27273% with 15 lines in your changes missing coverage. Please review.

Project coverage is 79.67%. Comparing base (fc96133) to head (959f2a3).
Report is 10 commits behind head on 2.4.

Files with missing lines	Patch %	Lines
internal/querycoordv2/task/scheduler.go	76.31%	6 Missing and 3 partials ⚠️
...ernal/querycoordv2/balance/multi_target_balance.go	0.00%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              2.4   #37939      +/-   ##
==========================================
- Coverage   80.62%   79.67%   -0.95%     
==========================================
  Files        1069     1069              
  Lines      166979   167025      +46     
==========================================
- Hits       134621   133083    -1538     
- Misses      27946    29520    +1574     
- Partials     4412     4422      +10     

Files with missing lines	Coverage Δ
internal/querycoordv2/balance/balance.go	94.11% <100.00%> (+0.29%)	⬆️
...erycoordv2/balance/channel_level_score_balancer.go	90.39% <100.00%> (+0.68%)	⬆️
...al/querycoordv2/balance/rowcount_based_balancer.go	95.08% <100.00%> (+0.03%)	⬆️
...ernal/querycoordv2/balance/score_based_balancer.go	98.96% <100.00%> (+1.74%)	⬆️
...ernal/querycoordv2/balance/multi_target_balance.go	83.20% <0.00%> (-0.42%)	⬇️
internal/querycoordv2/task/scheduler.go	90.00% <76.31%> (+1.06%)	⬆️

... and 98 files with indirect coverage changes

[tedxu]

/lgtm

[congqixia]

/approve

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: congqixia, weiliu1031

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• configs/OWNERS [congqixia]
• internal/querycoordv2/balance/OWNERS [congqixia]
• internal/querycoordv2/task/OWNERS [congqixia]
• pkg/util/OWNERS [congqixia]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment