Kubuntu release upgrader crashes early during upgrade from Kubuntu 23.10 to 22.04

[Mika Mäki]

Kubuntu release upgrader crashes during the early stages of the upgrade process before downloading the new packages. The upgrader also took an unusually long time to start, as it took several minutes for the upgrade window to appear after entering the sudo password for the upgrader. These symptoms started after my first attempt to upgrade from Kubuntu 23.10 to 24.04 was automatically canceled by the upgrader due to network connectivity issues during the package download. Rebooting the computer did not help.

During the upgrade process the following was printed to the console:
```
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
exitMainLoopMidFlight
Please call QDesktopServices::unsetUrlHandler() before destroying a registered URL handler object.
Support for destroying a registered URL handler object is deprecated, and will be removed in Qt 6.6.
Please call QDesktopServices::unsetUrlHandler() before destroying a registered URL handler object.
Support for destroying a registered URL handler object is deprecated, and will be removed in Qt 6.6.
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-mika'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-mika'
kf.service.services: The desktop entry file "/usr/share/applications/qemu.desktop" has Type= "Application" but no Exec line
kf.service.sycoca: Invalid Service : "/usr/share/applications/qemu.desktop"
kf.service.services: The desktop entry file "/usr/share/applications/org.freedesktop.Xwayland.desktop" has Type= "Application" but no Exec line
kf.service.sycoca: Invalid Service : "/usr/share/applications/org.freedesktop.Xwayland.desktop"

[Parent 129374, Main Thread] WARNING: Theme parsing error: gtk.css:1:21: Failed to import: Error opening file /home/mika/snap/firefox/4483/.config/gtk-3.0/colors.css: No such file or directory: 'glib warning', file /build/firefox/parts/firefox/build/toolkit/xre/nsSigHandlers.cpp:187

(firefox:129374): Gtk-WARNING **: 15:16:01.358: Theme parsing error: gtk.css:1:21: Failed to import: Error opening file /home/mika/snap/firefox/4483/.config/gtk-3.0/colors.css: No such file or directory
Gtk-Message: 15:16:01.379: Failed to load module "colorreload-gtk-module"
Gtk-Message: 15:16:01.380: Failed to load module "window-decorations-gtk-module"
[GFX1-]: More than 1 GPU from same vendor detected via PCI, cannot deduce device

[GFX1-]: More than 2 GPUs detected via PCI, secondary GPU is arbitrary

[Parent 129374, Main Thread] WARNING: OnCloseSessionDone error: Timeout was reached: 'glib warning', file /build/firefox/parts/firefox/build/toolkit/xre/nsSigHandlers.cpp:187

** (firefox:129374): WARNING **: 15:16:47.647: OnCloseSessionDone error: Timeout was reached
```

ProblemType: Bug
DistroRelease: Ubuntu 23.10
Package: ubuntu-release-upgrader-core 1:23.10.14
ProcVersionSignature: Ubuntu 6.5.0-42.42-generic 6.5.13
Uname: Linux 6.5.0-42-generic x86_64
NonfreeKernelModules: zfs nvidia_modeset nvidia
ApportVersion: 2.27.0-0ubuntu5
Architecture: amd64
CasperMD5CheckResult: unknown
CrashDB: ubuntu
Date: Tue Jul 9 15:15:46 2024
InstallationDate: Installed on 2020-05-22 (1509 days ago)
InstallationMedia: Kubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to mantic on 2024-07-09 (0 days ago)
VarLogDistupgradeAptHistorylog:
 Start-Date: 2024-07-09 14:50:35
 Requested-By: mika (1000)
 End-Date: 2024-07-09 14:50:35
VarLogDistupgradeAptlog:
 Log time: 2024-07-09 14:50:03.211937
 Log time: 2024-07-09 14:50:33.851485
 Log time: 2024-07-09 15:15:44.422011
 Log time: 2024-07-09 15:15:46.952144
VarLogDistupgradeApttermlog:
 Log started: 2024-07-09 14:50:35
 Log ended: 2024-07-09 14:50:35
VarLogDistupgradeTermlog: