Clean up imports in openmc/deplete/__init__.py
Clean up imports in openmc/deplete/__init__.py

mit-crpg/openmc,walshjon/openmc,walshjon/openmc,paulromano/openmc,smharper/openmc,mit-crpg/openmc,liangjg/openmc,liangjg/openmc,smharper/openmc,amandalund/openmc,liangjg/openmc,mit-crpg/openmc,mit-crpg/openmc,smharper/openmc,paulromano/openmc,amandalund/openmc,paulromano/openmc,walshjon/openmc,shikhar413/openmc,smharper/openmc,shikhar413/openmc,shikhar413/openmc,shikhar413/openmc,amandalund/openmc,amandalund/openmc,walshjon/openmc,paulromano/openmc,liangjg/openmc