perf: OOM investigations of map-only pipelines

[jaychia]

Investigations on OOM issues for map-only pipelines.

Tracking actual memory usage

Adds memray tracking to report the actual memory usage vs requested memory usage on our Ray tracing tool

Mock workload

Adds benchmarking/ooms/big_task_heap_usage.py which is a script that runs 2 UDFs with big heap memory usage (but small inputs/outputs)

This can be run using:

uv run tools/gha_run_cluster_job.py benchmarking/ooms/big_task_heap_usage.py --daft-wheel-url  --branch jay/big-materialization-ooms -- --num-partitions=64 --inflation-factor=8000000 --deflation-factor=8000000

Unit tests for memory usage

Unit tests to check our requested vs actual memory usage for selected plans

[codspeed-hq]

CodSpeed Performance Report

Merging #3558 will degrade performances by 28.56%

_{Comparing jay/big-materialization-ooms (60eed9d) with main (e148248)}

Summary

❌ 1 regressions
✅ 26 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	jay/big-materialization-ooms	Change
❌	test_iter_rows_first_row[100 Small Files]	142.9 ms	200.1 ms	-28.56%

[codecov]

Codecov Report

Attention: Patch coverage is 42.10526% with 11 lines in your changes missing coverage. Please review.

Project coverage is 77.79%. Comparing base (35ed63c) to head (2c4246f).

Files with missing lines	Patch %	Lines
daft/runners/ray_tracing.py	9.09%	10 Missing ⚠️
daft/runners/ray_metrics.py	87.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3558      +/-   ##
==========================================
- Coverage   77.81%   77.79%   -0.02%     
==========================================
  Files         716      716              
  Lines       87987    88000      +13     
==========================================
- Hits        68463    68461       -2     
- Misses      19524    19539      +15     

Files with missing lines	Coverage Δ
daft/runners/ray_metrics.py	58.24% <87.50%> (+2.94%)	⬆️
daft/runners/ray_tracing.py	61.29% <9.09%> (-1.89%)	⬇️

... and 4 files with indirect coverage changes