[clang-tools-extra] [llvm] [clang-tidy][NFC] Remove the `ObjCModuleTest.cpp` unit test (PR #185832)

[Haojian Wu via cfe-commits]

https://github.com/hokein approved this pull request.

Sorry for the delay. Removing it looks good to me as we already have the lit tests.

https://github.com/llvm/llvm-project/pull/185832