Update benchmarks

[seddonym]

Makes a couple of tweaks to the benchmarking code - in particular, remove the warnings triggered by just benchmark-local.

[codspeed-hq]

CodSpeed Performance Report

Merging #255 will improve performances by ×3.6

_{Comparing update-benchmarks (78ac056) with main (f6d1c4b)}

Summary

⚡ 2 improvements
✅ 21 untouched
⏩ 21 skipped¹

Benchmarks breakdown

	Mode	Benchmark	BASE	HEAD	Change
⚡	Simulation	test_build_django_from_cache_a_few_misses[15]	156.6 ms	130.4 ms	+20.1%
⚡	Simulation	test_build_django_from_cache_a_few_misses[350]	825.4 ms	230.3 ms	×3.6

Footnotes

1. 21 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩