[docs] fix typo (#8013)
## Summary
Fix a typo in the docs for quote style.
> a = "a string without any quotes"
> b = "It's monday morning"
> Ruff will change a to use single quotes when using quote-style =
"single". However, a will be unchanged, as converting to single quotes
would require the inner ' to be escaped, which leads to less readable
code: 'It\'s monday morning'.
It should read "However, **b** will be unchanged".
## Test Plan
N/A.