GPS/location services don't work with Maps after Bookworm upgrade

[wibble]

The wiki entries certainly need updating - I'll do it if nobody else has by the time I've got something I'm confident in. The AGPS data can now be uploaded using mmcli which does it using QMI rather than AT commands. I'm not clear on whether it sets the time though, which I think was important for being able to use the AGPS data. There still seems to be a gap around where responsibility for triggering the AGPS upload and (if necessary) time setting lies, and ModemManager doesn't have an API for checking its validity (don't want to repeat download/upload if data is still valid). If you hit polkit restrictions using mmcli then sudo will work around it until we've got something 'proper' that can get its own permissions config.