Also install c10d headers with .h extension (#73422)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/73422
Fixes https://github.com/pytorch/pytorch/issues/73421
ghstack-source-id: 149978120
Test Plan: None
Reviewed By: cbalioglu
Differential Revision: D34475711
fbshipit-source-id: 9e4d1d57021cbff51f53762b32bbfffbf3f81c4c
(cherry picked from commit 72ff35e28242132cf20e538d43ad3b63b3e497b1)
