red_knot_python_semantic: avoid adding `callable_ty` to `CallBindingError`
This is a small tweak to avoid adding the callable `Type` on the error
value itself. Namely, it's always available regardless of the error, and
it's easy to pass it down explicitly to the diagnostic generating code.
It's likely that the other `CallBindingError` variants will also want
the callable `Type` to improve diagnostics too. This way, we don't have
to duplicate the `Type` on each variant. It's just available to all of
them.
Ref https://github.com/astral-sh/ruff/pull/16239#discussion_r1962352646