Setup: I have installed Oracle Virtualbox 6.1.40 on my Windows 11 host. Running an Ubuntu 21.10 VM.
Since, Ubuntu 21.10 has reached EOL, I have tried to upgrade it referring to Upgrade Ubuntu desktop. I am getting the following error. What would be the reason?
$ sudo apt update
Ign:1 http://in.archive.ubuntu.com/ubuntu impish InRelease
Ign:2 http://security.ubuntu.com/ubuntu impish-security InRelease
Ign:3 http://in.archive.ubuntu.com/ubuntu impish-updates InRelease
Err:4 http://security.ubuntu.com/ubuntu impish-security Release
404 Not Found [IP: 91.189.91.39 80]
Ign:5 http://in.archive.ubuntu.com/ubuntu impish-backports InRelease
Err:6 http://in.archive.ubuntu.com/ubuntu impish Release
404 Not Found [IP: 91.189.91.38 80]
Err:7 http://in.archive.ubuntu.com/ubuntu impish-updates Release
404 Not Found [IP: 91.189.91.38 80]
Err:8 http://in.archive.ubuntu.com/ubuntu impish-backports Release
404 Not Found [IP: 91.189.91.38 80]
Reading package lists... Done
E: The repository 'http://security.ubuntu.com/ubuntu impish-security Release' no longer has a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://in.archive.ubuntu.com/ubuntu impish Release' no longer has a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://in.archive.ubuntu.com/ubuntu impish-updates Release' no longer has a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://in.archive.ubuntu.com/ubuntu impish-backports Release' no longer has a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
