Revert "Update mypy to 1.4.1 (#91983)"
This reverts commit 634659e262f82bbc76aa776119c9fea079fbffe3.
Reverted https://github.com/pytorch/pytorch/pull/91983 on behalf of https://github.com/malfet due to It's dependent change was reverted, so reverting this one as well, to keep CI clean ([comment](https://github.com/pytorch/pytorch/pull/91983#issuecomment-1636059709))
