[clang] [clang-format] Limit how much work guessLanguage() can do (PR #78925)

[Owen Pan via cfe-commits]

owenca wrote:

@HighCommander4 I got a better idea. It seems that we don't need to add the parameter! See #82957. I think all you need to do is to call `getStyle()` with the default `""` for the `StringRef Code` argument to skip the Objective-C guesser.

https://github.com/llvm/llvm-project/pull/78925