[CoreML] Use CoreMLTools Main Branch

[YifanShenSZ]

When we were prototyping the integration between ExecuTorch and CoreML, we were using the prototype branch executorch_integration

...
echo "${green}ExecuTorch: Checking out 'executorch_integration' branch in coremltools repo."
git checkout executorch_integration
...

in backends/apple/coreml/scripts/install_requirements.sh

Now that we have a more mature integration and have all necessary functionalities in main branch, it's time to use main branch now

Fix issue 1665

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/1666

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[facebook-github-bot]

@shoumikhin has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[DawerG]

Thanks @YifanShenSZ. Can you please ensure that there are no more references to executorch_integration branch in this repo?

And, after this PR is merged, let's delete executorch_integration branch from coremltools repo.

[YifanShenSZ]

Grepped my local branch and confirmed no executorch_integration left in source

[facebook-github-bot]

@shoumikhin merged this pull request in 0e17257.