Revert "Add objective-c language support in CMake (#80432)"
This reverts commit 182870f4a7c6d1fc6198187dee9262aa68a97115.
Reverted https://github.com/pytorch/pytorch/pull/80432 on behalf of https://github.com/malfet due to Broke ios-12-5-1-x86-64-coreml builds, see https://github.com/pytorch/pytorch/runs/7105704349?check_suite_focus=true
