when switching themes using home-manager specialisations, the user
environment in /etc/profiles/per-user is not updated (managed by nixos),
so we create a symlink here to force it to use the current hm config's
spicetify (.local/bin has higher priority)
this is a workaround at best, a hack at worst. should probably somehow
make /etc/profiles irrelevant and use something else user-managed.
