get_batch() called torch.nn.functional.interpolate on a mismatched
noise mask but discarded the result, so the mask kept its original
size. The height check was also missing the *8 pixel scale. When a
rebatched latent carried a noise mask that did not match samples * 8
(e.g. from SetLatentNoiseMask, which stores masks unscaled), the
unresized mask later failed to concatenate with another latent's
default mask and raised a size-mismatch RuntimeError.
Assign the interpolate result back to mask and compare the height
against shape[-2] * 8.
