Support the sshfs method for TRAMP

[catern]

Emacs 28.1 added a new sshfs method for TRAMP. dired-rsync should support this. Probably it would be best to just rsync the files locally - the sshfs approach means there's no need for any port forwarding even if the transfer is remote-to-remote.

(I admit I haven't actually tested whether dired-rsync supports this)

[stsquad]

I think there is nothing to do here. sshfs just appears as a local file-system from the point of view of emacs do it should generate a local to local rsync command.