Revert "add Half support for BatchNorm on CPU (#102070)"
This reverts commit b6a1d3fb97ca8eeccf15a4c495fdd1af4b197f88.
Reverted https://github.com/pytorch/pytorch/pull/102070 on behalf of https://github.com/clee2000 due to I'm very sorry but it looks like #106543 was not fixed, I still see it failing on main https://hud.pytorch.org/pytorch/pytorch/commit/b6a1d3fb97ca8eeccf15a4c495fdd1af4b197f88 https://github.com/pytorch/pytorch/actions/runs/6185704949/job/16793975677 ([comment](https://github.com/pytorch/pytorch/pull/102070#issuecomment-1719747065))
