Add descriptive error causes for reduce values errors

[Bobronium]

No description provided.

[codspeed-hq]

Merging this PR will improve performance by 29.8%

⚡ 1 improved benchmark
✅ 357 untouched benchmarks

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	test_individual_cases[copium-cpython:91610:repeating_atomic]	29.4 µs	22.7 µs	+29.8%

---

_{Comparing descriptive-reduce-error-causes (62d5c6e) with main (4bcdb4f)¹}

Footnotes

1. No successful run was found on main (475641d) during the generation of this report, so 4bcdb4f was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩