Upgrade python/pybind11 to v2.6.2 am: c1e4e8e441

Original change: https://android-review.googlesource.com/c/platform/external/python/pybind11/+/1561635

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Id500d91c1a727f6ea89566747c9be9d7dd49377e