ruff

bc0427e5 - [ty] Emit "arguments after `**` must be a mapping" before overload resolution (#22921)

[ty] Emit "arguments after `**` must be a mapping" before overload resolution (#22921) ## Summary Closes astral-sh/ty#2653 Move the KeywordsNotAMapping check from bind.rs to builder.rs, matching the existing pattern for starred argument iterability. This ensures users see "must be a mapping type" instead of "no matching overload" when passing a non-mapping **kwargs to an overloaded function. ## Test Plan Added test case for **kwargs with non-mapping types on overloaded functions in function.md.