ruff

77b2cee2 - [ty] Add functions for revealing assignability/subtyping constraints (#20217)

[ty] Add functions for revealing assignability/subtyping constraints (#20217) This PR adds two new `ty_extensions` functions, `reveal_when_assignable_to` and `reveal_when_subtype_of`. These are closely related to the existing `is_assignable_to` and `is_subtype_of`, but instead of returning when the property (always) holds, it produces a diagnostic that describes _when_ the property holds. (This will let us construct mdtests that print out constraints that are not always true or always false — though we don't currently have any instances of those.) I did not replace _every_ occurrence of the `is_property` variants in the mdtest suite, instead focusing on the generics-related tests where it will be important to see the full detail of the constraint sets. As part of this, I also updated the mdtest harness to accept the shorter `# revealed:` assertion format for more than just `reveal_type`, and updated the existing uses of `reveal_protocol_interface` to take advantage of this.