Shaman cannot handle cases where the storage path is a symlink (i.e. cases
where `filepath.EvalSymlinks(storagePath)` does not return `storagePath`).
This caused macOS devices to fail the unit tests, because macOS uses a
symlinked path for temporary files.
This commit changes the unit tests, to always use the real path instead of
the OS-provided symlink. This does *not* fix the actual issue in Shaman,
for that see T99965.
424b87d1d3