Revert "Cleanup custom op library after each custom_op test (#100980)"
This reverts commit d0d81652306bcf88f804a11a0061bcee847c6e5d.
Reverted https://github.com/pytorch/pytorch/pull/100980 on behalf of https://github.com/jeanschmidt due to breaking internal builds ([comment](https://github.com/pytorch/pytorch/pull/100980#issuecomment-1548336634))