[llvm] [NFC][stlextras] Delete repetition of are (PR #101977)

[Andrey Timonin via llvm-commits]

EtoAndruwa wrote:

> You can add `NFC` to the PR title



> You can add `NFC` to the PR title

Hello! Thank you for reviewing this patch and for your advice. Fixed.

https://github.com/llvm/llvm-project/pull/101977