Revert "Fix conda install on distributions with strict POSIX sh (#91371)"
This reverts commit 57dcd93c4103c6db043f341a0242596a42188081.
Reverted https://github.com/pytorch/pytorch/pull/91371 on behalf of https://github.com/kit1980 due to trunk / cuda11.6-py3.10-gcc7-sm86 / test (slow, 1, 2, linux.g5.4xlarge.nvidia.gpu) started to fail after this PR with mypy error
