Use pytorch bot's labeler (#121762)
Change corresponds to https://github.com/pytorch/test-infra/pull/4995
Testing (very light) in https://github.com/malfet/deleteme/pull/81
Should help with https://github.com/pytorch/test-infra/issues/4950
Pull Request resolved: https://github.com/pytorch/pytorch/pull/121762
Approved by: https://github.com/huydhn
