Link MPS and CoreML delegate library into portable_lib (#4040)

Summary:
As titled. MPS and CoreML should be linked into portable_lib on mac.

Pull Request resolved: #4040

Test Plan: See CI job works?

Reviewed By: dbort

Differential Revision: D59351891

Pulled By: larryliu0820

fbshipit-source-id: 2d551b84b1fd09995ef3cbf0594b2e1b46854276

README-wheel.md

@@ -17,6 +17,7 @@ restrictions:
 * Only the [XNNPACK backend
   delegate](https://pytorch.org/executorch/main/native-delegates-executorch-xnnpack-delegate.html)
   is linked into the prebuilt module
+* [macOS only] [Core ML](https://pytorch.org/executorch/main/build-run-coreml.html) and [MPS](https://pytorch.org/executorch/main/build-run-mps.html) backend delegates are linked into the prebuilt module.
 
 Please visit the [ExecuTorch website](https://pytorch.org/executorch/) for
 tutorials and documentation. Here are some starting points:

build/packaging/env_var_script_m1.sh

@@ -20,7 +20,5 @@ export CMAKE_ARGS="${CMAKE_ARGS:-}"
 CMAKE_ARGS="${CMAKE_ARGS} -DEXECUTORCH_BUILD_XNNPACK=ON"
 
 # When building for macOS, link additional backends into the pybindings runtime.
-
-# TODO(dbort): Make these build properly in the CI environment.
-# CMAKE_ARGS="${CMAKE_ARGS} -DEXECUTORCH_BUILD_COREML=ON"
-# CMAKE_ARGS="${CMAKE_ARGS} -DEXECUTORCH_BUILD_MPS=ON"
+CMAKE_ARGS="${CMAKE_ARGS} -DEXECUTORCH_BUILD_COREML=ON"
+CMAKE_ARGS="${CMAKE_ARGS} -DEXECUTORCH_BUILD_MPS=ON"