feat(shuffles): Determination logic for pre shuffle merge

[colin-ho]

Use pre shuffle merge if geometric mean of total number of partitions: sqrt(input * output) is >= 200.

I chose 200 to match shuffle_aggregation_default_partitions, which means shuffles for large aggregations will use pre-shuffle merge.

[codspeed-hq]

CodSpeed Performance Report

Merging #3674 will improve performances by 47.23%

_{Comparing colin/turn-on-pre-shuffle-merge (062143b) with main (a8d63dd)}

Summary

⚡ 1 improvements
✅ 26 untouched benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	test_show[100 Small Files]	23.5 ms	16 ms	+47.23%

[codecov]

Codecov Report

Attention: Patch coverage is 72.30769% with 18 lines in your changes missing coverage. Please review.

Project coverage is 76.27%. Comparing base (a8d63dd) to head (062143b).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
src/daft-physical-plan/src/ops/shuffle_exchange.rs	71.66%	17 Missing ⚠️
src/common/daft-config/src/python.rs	75.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3674      +/-   ##
==========================================
- Coverage   77.58%   76.27%   -1.31%     
==========================================
  Files         729      728       -1     
  Lines       92035    95211    +3176     
==========================================
+ Hits        71409    72626    +1217     
- Misses      20626    22585    +1959     

Files with missing lines	Coverage Δ
daft/context.py	87.65% <ø> (ø)
src/common/daft-config/src/lib.rs	82.27% <100.00%> (ø)
src/common/daft-config/src/python.rs	66.51% <75.00%> (+0.30%)	⬆️
src/daft-physical-plan/src/ops/shuffle_exchange.rs	59.03% <71.66%> (+8.25%)	⬆️

... and 33 files with indirect coverage changes