Add target_link_options_shared_lib to coremldelegate build (#3556)

Summary:
Backends use a static initializer to register themselves. We have an established solution to forcing the Apple linker to load the object files containing said initializer, so let's use it for CoreML.

Pull Request resolved: https://github.com/pytorch/executorch/pull/3556

Test Plan: Attempt to load a CoreML PTE from Python no longer fails with error about the backend not being registered

Reviewed By: mikekgfb

Differential Revision: D57136490

Pulled By: swolchok

fbshipit-source-id: 613d7f786fa47f34a94ee4eea7b2a81ef670a573