An unresolvable problem occurred while calculating the upgrade

[Yovan]

During the upgrade, there are two prompts

1)

"No valid mirror found

While scanning your repository information, no mirror entry for the
upgrade was found. This can happen if you run an internal mirror or
if the mirror information is out-of-date.

Do you want to rewrite your 'sources.list' file anyway? If you choose
'Yes' here, it will update all 'jammy' to 'kinetic' entries.
If you select 'No', the upgrade will cancel. "

2)

"Generate default sources?

After scanning your 'sources.list' no valid entry for 'jammy' was
found.

Should default entries for 'kinetic' be added? If you select 'No',
the upgrade will cancel. "

In Conclusion, the upgrade failed when running "sudo do-release-upgrade -m desktop"

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: ubuntu-release-upgrader-core 1:22.04.14
ProcVersionSignature: Ubuntu 5.15.0-56.62-generic 5.15.64
Uname: Linux 5.15.0-56-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.2
Architecture: amd64
CasperMD5CheckResult: unknown
CrashDB: ubuntu
CurrentDesktop: KDE
Date: Tue Dec 6 12:42:11 2022
InstallationDate: Installed on 2021-01-15 (689 days ago)
InstallationMedia: Kubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to jammy on 2022-12-06 (0 days ago)
mtime.conffile..etc.update-manager.release-upgrades: 2022-10-29T11:56:30.705046

[Yovan (navoytak)]

currently the sources.list file is amended to what is attached. Upgrade to 22.10 still fails due to NO_PUBKEY 871920D1991BC93C. See attached sources.list file.

Affects the following:
http://archive.ubuntu.com/ubuntu kinetic-updates InRelease
http://archive.ubuntu.com/ubuntu kinetic InRelease
http://security.ubuntu.com/ubuntu kinetic-security InRelease

[Yovan (navoytak)]

Attaching recreated gpg file with the Pubkey 871920D1991BC93C

[Yovan (navoytak)]

recreated the default trusted.gpg in /etc/apt/trusted.gpg.d/ mostly solved the issue of not being able to upgrade from 22.03 to 22.10. Previously i misinterpreted the message of moving every gpg files into /usr/share/keyrings/ .
Except for the file trusted.gpg, all gpg files are happily situated in /usr/share/keyrings , this kept the Ubuntu system happy for the upgrade to the latest Ubuntu 22.10