Fix docker builds for Python-3.6 (#69785)
Summary:
As [conda-4.11](https://anaconda.org/anaconda/conda/files?version=4.11.0) is no longer available for Python-3.6, stick to 4.10 for 3.6 builds
Fixes https://github.com/pytorch/pytorch/issues/69781
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69785
Reviewed By: seemethere, atalman
Differential Revision: D33026217
Pulled By: malfet
fbshipit-source-id: d742a1e79634ed62b3a941ba23a7a74f41c2f4cb
