ci: Remove daft tracing

[raunakab]

Overview

Daft tracing was enabled by default. However, this can negatively affect performance, so this PR opts to make daft-tracing disabled by default.

However, end-users can still choose to turn on daft-tracing by default (should they so wish) by adding the DAFT_ENABLE_RAY_TRACING=1 environment variable.

[codspeed-hq]

CodSpeed Performance Report

Merging #3692 will degrade performances by 32.34%

_{Comparing remove-daft-tracing (73ca820) with main (34d2036)}

Summary

⚡ 1 improvements
❌ 1 regressions
✅ 25 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	remove-daft-tracing	Change
⚡	test_iter_rows_first_row[100 Small Files]	197.1 ms	165.9 ms	+18.77%
❌	test_show[100 Small Files]	16.1 ms	23.8 ms	-32.34%

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.79%. Comparing base (34d2036) to head (73ca820).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3692   +/-   ##
=======================================
  Coverage   77.79%   77.79%           
=======================================
  Files         729      729           
  Lines       90477    90468    -9     
=======================================
- Hits        70384    70381    -3     
+ Misses      20093    20087    -6     

see 3 files with indirect coverage changes

[raunakab]

Example of a run: https://github.com/Eventual-Inc/Daft/actions/runs/12801013277.