[clang-tools-extra] [clang-tidy] Fix invalid fixit from modernize-use-ranges for nullptr used with std::unique_ptr (PR #127162)

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Andrewyuan34 wrote:

@HerrCai0907 Sorry for requesting your approval again, I really have no experience sending a PR.  
I appreciate your patience and feedback on my changes. Let me know if there's anything else I should improve.  
Thanks for your time! 😊

https://github.com/llvm/llvm-project/pull/127162