Fix reduction agg with numpy udf

[luweizheng]

What do these changes do?

Similar issue like #737

Check code requirements

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

[codecov]

Codecov Report

Merging #742 (f496ca1) into main (b1d828f) will decrease coverage by 5.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #742      +/-   ##
==========================================
- Coverage   93.34%   88.30%   -5.04%     
==========================================
  Files        1026     1026              
  Lines       79589    79589              
  Branches    16497    16497              
==========================================
- Hits        74290    70281    -4009     
- Misses       3616     7479    +3863     
- Partials     1683     1829     +146     

Flag	Coverage Δ
unittests	88.20% <100.00%> (-5.04%)	⬇️

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

Files	Coverage Δ
python/xorbits/_mars/dataframe/reduction/max.py	100.00% <100.00%> (ø)
python/xorbits/_mars/dataframe/reduction/mean.py	100.00% <100.00%> (ø)
python/xorbits/_mars/dataframe/reduction/min.py	100.00% <100.00%> (ø)

... and 144 files with indirect coverage changes

[codingl2k1]

LGTM