[libc++][NFC] Resolve Python 2 FIXME

We don't use Python 2 anymore, so let us do the recommended fix instead
of using the workaround made for Python 2.

Differential Revision: https://reviews.llvm.org/D107715

GitOrigin-RevId: f46f93b4786377dd7ee704ef2beedadfe4f05adf
4 files changed