BUG: index may not monotonic increasing in `DataFrameGroupbySortShuffle` op

[ChengjieLi28]

What do these changes do?

Related issue number

Fixes #xxxx

Check code requirements

• [ ] tests added / passed (if needed)
• [ ] Ensure all linting tests pass

[codecov[bot]]

Codecov Report

Merging #752 (1870c35) into main (f67ffd4) will decrease coverage by 3.74%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #752      +/-   ##
==========================================
- Coverage   93.58%   89.84%   -3.74%     
==========================================
  Files        1058     1058              
  Lines       79780    79783       +3     
  Branches    16504    16506       +2     
==========================================
- Hits        74659    71685    -2974     
- Misses       3446     6250    +2804     
- Partials     1675     1848     +173     

Flag	Coverage Δ
unittests	89.74% <100.00%> (-3.74%)	:arrow_down:

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...hon/xorbits/_mars/dataframe/groupby/aggregation.py	95.96% <100.00%> (+0.01%)	:arrow_up:

... and 122 files with indirect coverage changes