[clang] [clang-format][NFC] Upgrade SortIncludes option to a struct (PR #140497)

[Daan De Meyer via cfe-commits]

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

Thank you! FWIW, I went over the changes and they all look sensible to me

https://github.com/llvm/llvm-project/pull/140497