[clang-tools-extra] [Clang-Tidy] Fixed `cppcoreguidelines-init-variables` to handle ObjC for-in loops. (PR #191306)

[Dmitrii Kuragin via cfe-commits]

sstepashka wrote:

@vbvictor I am not sure if this PR should be blocked by the discussion. This PR doesn't change the existing status quo and only slightly improves the existing check the way it works right now.

Even if the project decided that ObjC is out-of-scope for the check and we'd like to disable it completely for ObjC, I'm also cool with that.

Is there anything specific what blocking the current PR I need to address? 

https://github.com/llvm/llvm-project/pull/191306