Create the foundation for testing CoreML export for wheels (#9381)

### Summary
As part of https://github.com/pytorch/executorch/issues/9019, this will
allow us to test CoreML support for wheels.

#### Why are we only selectively running the executor test? 

Our `macos-*-stable` runners do not have xcode, which is required to
build and run these tests. Only GitHub's `macos-*-xlarge` runners have
xcode. We currently run these CoreML tests on
[trunk](https://github.com/pytorch/executorch/blob/7c6d2f332861907391450974a481b6d8e04732ed/.github/workflows/trunk.yml#L444-L477),
which would be way too expensive to use GitHub's runner given the
frequency. So let's limit the runner tests to just the wheel jobs. I
will work with Test Infra to get Xcode into our runners.

### Test plan

* Wheel tests shouldn't change
* Test locally

```bash
$ GITHUB_WORKSPACE=$(dirname $(pwd)) REPOSITORY=$(basename $(pwd)) python .ci/scripts/wheel/test_macos.py
```