When a multigpu clone ModelPatcher is garbage collected, LoadedModel._switch_parent
switches the weakref to point at the parent (main) ModelPatcher. However, it was not
updating LoadedModel.device, leaving it with the old clone's device (e.g., cuda:1).
On subsequent runs, this stale device was passed to ModelPatcherDynamic.load(), causing
an assertion failure (device_to != self.load_device).
Amp-Thread-ID: https://ampcode.com/threads/T-019d3f5c-28c5-72c9-abed-34681f1b54ba
Co-authored-by: Amp <amp@ampcode.com>