Upgrade from mantic to noble shows a debconf prompt

[Skia]

Reproducer:

* Run Ubuntu Studio Mantic in a VM
* Run `do-release-upgrade -d` to upgrade it to Noble
* After the package download phase, the packages upgrade starts, and you quickly get prompted by jackd2 asking `Enable realtime process priority?`

This can be avoided with `export DEBIAN_FRONTEND=noninteractive`, that's why it didn't show up in the CI, but we can't expect users to rely on this.

I've attached a screenshot of the prompt, that contains more details on what exactly is asked.

[Erich Eickmeyer (eeickmeyer)]

This has never been a problem in previous upgrades, so something in jackd2 must've changed in the debian packaging. We don't maintain this in Ubuntu but rely on syncs from Debian. Furthermore, we usually force this in when upgrading, so I'm surprised this is even happening. Perhaps we can add it as a quirk for `ubuntu-release-upgrader` to help with?

[Steve Langasek (vorlon)]

u-r-u shouldn't be quirking away debconf prompts. The package in question needs to be fixed to not pop a debconf prompt on an upgrade from a stock install. "rely on syncs from Debian" is not a justification here.

[Julian Andres Klode (juliank)]

This should be fixed in the jackd2 packagee