[clang-tools-extra] [clang-tidy] Fix OOB access in `FormatStringConverter` with signed chars (PR #169215)

[via cfe-commits]

zeyi2 wrote:

The python script inside CI container gives `UnicodeEncodeError: 'charmap' codec can't encode characters in position 1451-1454: character maps to <undefined>`, which is weird. I'm trying to fix this issue.

https://github.com/llvm/llvm-project/pull/169215