[Sema] Fix `Differentiable` derived conformances. (#22119)
* [Sema] Fix `Differentiable` derived conformances.
Associated structs can inherit from `AdditiveArithmetic` or `VectorNumeric`
if their member's associated type inherit from the protocol, not the member's
type itself.
Revert unuseful refactoring from #22114.
* Update `tensorflow-swift-apis` version.
Use updated+fixed version.
