The docs for rule linting rule D203 fell afoul of last week's black upgrade.
In this commit black was run: 597c5f9
Which formatted the example code for the lint, and removed the blank line that the example is supposed to be showcasing: 597c5f9#diff-2f8b0cca706f79d3614697888a3fb04bad222bb0f5849b08c2411ad112ea3351L121
The two examples now appear equal:

https://docs.astral.sh/ruff/rules/one-blank-line-before-class/
This was released yesterday in 0.6.0 and the website was updated, making the examples on the website now invalid