avoid upcasting by assigning dtype to noise tensor (#3713)
* avoid upcasting by assigning dtype to noise tensor
* make style
* Update train_unconditional.py
* Update train_unconditional.py
* make style
* add unit test for pickle
* revert change
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Co-authored-by: root <root@orttrainingdev8.d32nl1ml4oruzj4qz3bqlggovf.px.internal.cloudapp.net>
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>
Co-authored-by: Prathik Rao <prathikrao@microsoft.com@orttrainingdev8.d32nl1ml4oruzj4qz3bqlggovf.px.internal.cloudapp.net>
