Enhancement: Make `mount` command support macOS using macFUSE 4.x

Restic now uses a different FUSE library for mounting snapshots and making them
available as a FUSE filesystem using the `mount` command. This adds support for
macFUSE 4.x which can be used to make this work on recent macOS versions.

https://github.com/restic/restic/issues/3096
https://github.com/restic/restic/pull/4024
