Revert "Remove remaining global `set_default_dtype` calls from tests (#107246)"
This reverts commit aa8ea1d787a9d21b064b664c5344376265feea6c.
Reverted https://github.com/pytorch/pytorch/pull/107246 on behalf of https://github.com/facebook-github-bot due to Diff reverted internally ([comment](https://github.com/pytorch/pytorch/pull/107246#issuecomment-1693838522))
