Added pyarrow to OSX build script

[WillAyd]

• closes BLD/TST: add pyarrow on CI to macosx build #18714
• tests added / passed
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

[jreback]

see #18715

seems numpy is getting upgraded here

[codecov]

Codecov Report

Merging #18766 into master will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #18766      +/-   ##
==========================================
- Coverage   91.61%    91.6%   -0.02%     
==========================================
  Files         153      153              
  Lines       51367    51367              
==========================================
- Hits        47061    47054       -7     
- Misses       4306     4313       +7

Flag	Coverage Δ
#multiple	89.46% <ø> (ø)	⬆️
#single	40.76% <ø> (-0.12%)	⬇️

Impacted Files	Coverage Δ
pandas/io/gbq.py	25% <0%> (-58.34%)	⬇️
pandas/core/frame.py	97.81% <0%> (-0.1%)	⬇️
pandas/util/testing.py	82.52% <0%> (+0.19%)	⬆️

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[WillAyd]

Thanks for the info. Assuming this will be addressed within one of those threads I'm going to close this out