This appears to be an issue introduced by NNunetv2 developers. This package is a dependency of TotalSegmentator.
A possible workaround is to open the NNunet Slicer module which is used for installing versions of the package. Choose to install nnunetv2<2.6 as it seems like the nnunetv2 2.6.0 version introduced this error that requires torch 2.6.0 and later for the CPU version of GradScaler.
Unfortunately, on macOS Slicer factory builds are still x86_64 builds with no native arm64 build. The latest version of torch supported on x86_64 macOS is torch 2.2.x. Slicer developers have been actively working to update a whole list of dependencies to be able to support native arm64 builds. Things are still in progress, but hopefully these type of issues on macOS will be resolved soon for users of macOS on Apple Silicon M based Macs.