ruff

734d75ae - [ty] Check for unsatisfiable bodies before existentially quantifying (#29504)

[ty] Check for unsatisfiable bodies before existentially quantifying (#29504) When we existentially quantify a BDD, we calculate `∃X . B` for some set of typevars `X` and some BDD `B`. If the BDD is never satisfiable, this is equivalent to `∃X . false`, which can be further simplified to `false`. We expect this to be performance neutral at the moment, since `reduce_inferable` will already simplify the resulting quantified BDD down to `false` in most cases. We've extracted it for separate review out of #29027, where is has a much more pronounced impact, since it prevents us from creating existential nodes that we have to repeatedly walk through during solution extraction.