pytorch

23bdb570 - Reland: Enable `dim=None` for `torch.sum` (#79881)

Reland: Enable `dim=None` for `torch.sum` (#79881) Part of #29137 Reland of #75845 Pull Request resolved: https://github.com/pytorch/pytorch/pull/79881 Approved by: https://github.com/albanD, https://github.com/kulinseth