Remove CUDA10.2 + gcc 9 in CI (#62609)
Summary:
This is an invalid combination because CUDA10.2 does not support gcc>8
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62609
Reviewed By: iramazanli
Differential Revision: D30057292
Pulled By: seemethere
fbshipit-source-id: 7cb0fa8401e80297846b0fcb5e0ecaa435b101be
