[ruff] Stabilize invalid-assert-message-literal-argument (RUF040)

[ntBre]

Summary

Stabilizes RUF040 and fixes a very minor typo in the docs. The tests are already in the right place.

Test Plan

0 issues or PRs

[codspeed-hq]

CodSpeed Performance Report

Merging #16646 will degrade performances by 12.73%

_{Comparing brent/ruf040-0.10 (d4c46ba) with micha/ruff-0.10 (85f7871)}

Summary

❌ 1 regressions
✅ 31 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
❌	red_knot_check_file[incremental]	4.8 ms	5.5 ms	-12.73%

[github-actions]

ruff-ecosystem results

Linter (stable)

ℹ️ ecosystem check detected linter changes. (+3 -0 violations, +0 -0 fixes in 3 projects; 52 projects unchanged)

bokeh/bokeh (+1 -0 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --no-preview --select ALL

+ tests/unit/bokeh/io/test_state.py:47:43: RUF040 Non-string literal used as assert message

pandas-dev/pandas (+1 -0 violations, +0 -0 fixes)

+ pandas/tests/series/accessors/test_cat_accessor.py:43:37: RUF040 Non-string literal used as assert message

pytest-dev/pytest (+1 -0 violations, +0 -0 fixes)

+ testing/_py/test_local.py:218:26: RUF040 Non-string literal used as assert message

Changes by rule (1 rules affected)

code	total	+ violation	- violation	+ fix	- fix
RUF040	3	3	0	0	0

Linter (preview)

✅ ecosystem check detected no linter changes.

[ntBre]

The ecosystem checks look like true positives to me. This might catch some bugs right away.