This isn't a problem on Scarthgap, so I looked into what has changed, and I found the two changes which introduce the dependency loop.

 

1. glib-2.0 now adds gobject-introspection to DEPENDS if gobject-introspection-data is in DISTRO_FEATURES

2. systemd now inherits mime class and adds shared-mime-info to DEPENDS (this also adds libxml2 to DEPENDS)

 

Reverting these two changes and the dependency loop between python and bluez5 disappears.