[clang-tools-extra] [clang-tidy] 'modernize-use-starts-ends-with': fixed false positives on `find` and `rfind` (PR #129564)

[Baranov Victor via cfe-commits]

vbvictor wrote:

Rebase and PR-checks are done, ready to merge 

https://github.com/llvm/llvm-project/pull/129564