ubuntu upgrade to noble failed because it couldn't remove postgresql12-wal2json

[Odin Hørthe Omdal]

This stopped without telling why. The logs pointed towards postgres. After some failed attempts I found the denylist was actually shipped in the installer, but it seems a bit too strict.

```
root@kaa:/tmp/ubuntu-release-upgrader-xjd4g5rx# cat removal_denylist.cfg
# deny list of packages that should never be removed
ubuntu-standard
ubuntu-minimal
ubuntu-desktop$
kubuntu-desktop
xubuntu-desktop
lubuntu-desktop
mythbuntu-desktop
ubuntustudio-desktop
ubuntu-mate-core
ubuntu-mate-desktop
# ubuntu-release-upgrader should not remove itself or update-manager
update-manager$
update-manager-core
ubuntu-release-upgrader-core
# if for example postgresql-10 is purged the cluster can be dropped which we
# should prevent (LP: #871893, #1825563)
^postgresql-.*[0-9]\.[0-9].*
^postgresql-.*[0-9][0-9].*
# the upgrade runs in it
^screen$
# the upgrade might be run over ssh
^openssh-server$
```

Uninstalling the wal2json extension fixed it.

# apt remove postgresql-12-wal2json

I expected Ubuntu to just remove this, -- I've cleaned up he 12 cluster into 14 previously. It is a bit bothersome having to do that manually all the time, this is just a development machine, though I understand some people will be more afraid of their production clusters. Still think an auto-upgrade or migration or at least an option to just pg_dump the lot and remiport would be okay for desktop ubuntu installs.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: ubuntu-release-upgrader-core 1:22.04.19
ProcVersionSignature: Ubuntu 6.8.0-38.38~22.04.1-generic 6.8.8
Uname: Linux 6.8.0-38-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: unknown
CrashDB: ubuntu
CrashReports:
 640:1000:117:9919263:2024-07-27 18:20:10.349304025 +0200:2024-07-27 21:05:57.490952459 +0200:/var/crash/_opt_vivaldi_vivaldi-bin.1000.crash
 600:111:117:37:2024-07-27 21:05:58.664952356 +0200:2024-07-27 21:05:58.664952356 +0200:/var/crash/_opt_vivaldi_vivaldi-bin.1000.uploaded
 644:0:117:1813:2024-07-20 06:54:30.287886987 +0200:2024-07-27 17:31:29.619326964 +0200:/var/crash/v4l2loopback-dkms.0.crash
 644:1000:117:0:2024-07-27 18:20:10.349304025 +0200:2024-07-27 18:20:10.349304025 +0200:/var/crash/_opt_vivaldi_vivaldi-bin.1000.upload
 644:0:117:2352:2024-07-20 06:54:35.563946474 +0200:2024-07-27 17:31:29.621326977 +0200:/var/crash/virtualbox-dkms.0.crash
CurrentDesktop: ubuntu:GNOME
Date: Sun Jul 28 12:54:04 2024
InstallationDate: Installed on 2018-08-28 (2161 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to jammy on 2024-07-28 (0 days ago)
VarLogDistupgradeAptHistorylog:
 Start-Date: 2024-07-28 12:52:50
 Requested-By: odin (1000)
 End-Date: 2024-07-28 12:52:51
VarLogDistupgradeAptlog:
 Log time: 2024-07-28 12:52:42.583505
 Log time: 2024-07-28 12:52:48.167922
VarLogDistupgradeApttermlog:
 Log started: 2024-07-28 12:52:50
 Log ended: 2024-07-28 12:52:51
mtime.conffile..etc.update-manager.release-upgrades: 2024-07-28T11:02:53.335723