Raise warning when calling collectives on non-member group objects (#67639)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67639
Due to BC considerations, we cannot directly error out, as that
might break existing applications. Raise warnings first to improve
debuggability.
cc pietern mrshenli pritamdamania87 zhaojuanmao satgera rohan-varma gqchen aazzolini osalpekar jiayisuse SciPioneer H-Huang
Test Plan: Imported from OSS
Reviewed By: rohan-varma
Differential Revision: D32075151
Pulled By: mrshenli
fbshipit-source-id: 5680d420f5f6cd3f74a36616c03350e8a976b363
