move to a private nextcloud instance
in #31540 (moved), we agreed to delegate running a dedicated Nextcloud instance to riseup.
this ticket tracks the next steps, so far:
- create the private instance (riseup)
- point DNS at the private instance (TPA)
- make sure HTTPS works (riseup?)
#32332 (moved) set up LDAP integration, somehow (service admins + riseup)- move content and users over (gaba + pili + teams)