[pyflakes] Fix backslash in docs (F621)

[MeGaGiGaGon]

Summary

This fixes the docs for expressions-in-star-assignment (F621) having a backslash \ before the left shifts <<. I'm not sure why this happened in the first place, as the docstring looks fine, but putting the << inside a code block fixes it. I was not able to track down the source of the issue either. The only other rule with a << is missing-whitespace-around-bitwise-or-shift-operator (E227), which already has it in a code block.

Old docs page:

In Python 3, no more than 1 \<< 8 assignments are allowed before a starred expression, and no more than 1 \<< 24 expressions are allowed after a starred expression.

New docs page:

In Python 3, no more than 1 << 8 assignments are allowed before a starred expression, and no more than 1 << 24 expressions are allowed after a starred expression.

Test Plan

N/A, no tests/functionality affected.

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

[ntBre]

Nice, thanks! I wonder if mkdocs is trying to escape an HTML tag or something.