ci: add a tool to launch workloads on cluster

[jaychia]

Example usage:

uv run tools/gha_run_cluster_job.py .github/working-dir/simple.py

[codspeed-hq]

CodSpeed Performance Report

Merging #3516 will improve performances by 59.18%

_{Comparing jay/gha-launcher (a14196c) with main (ad175ae)}

Summary

⚡ 1 improvements
✅ 16 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	jay/gha-launcher	Change
⚡	test_iter_rows_first_row[100 Small Files]	187.6 ms	117.8 ms	+59.18%

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.59%. Comparing base (3a8cece) to head (a14196c).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3516      +/-   ##
==========================================
- Coverage   77.60%   77.59%   -0.01%     
==========================================
  Files         707      708       +1     
  Lines       86174    86154      -20     
==========================================
- Hits        66875    66853      -22     
- Misses      19299    19301       +2     

see 10 files with indirect coverage changes