[acc_ops] No longer mark acc_ops.cat as unary (#70365)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70365
We should only mark ops as unary if they should have a single fx.Node input. However, `cat` has a sequence of `tensors` input.
Reviewed By: alexbeloi
Differential Revision: D33299988
fbshipit-source-id: db3581eaee4ad9d2358eed01ec9027825f58f220
