Odoo v16 - Error on apt update after installation on ubuntu 22.04. + Proposed solution

[tbanevicius]

After executing script and running apt-update encountered error:

Err:6 http://mirrors.edge.kernel.org/ubuntu xenial InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
Reading package lists... Done
W: GPG error: http://mirrors.edge.kernel.org/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
E: The repository 'http://mirrors.kernel.org/ubuntu xenial InRelease' is not signed.
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.

OS: Ubuntu 22.04.4 LTS

Current solution I've found to execute these commands which will add keys:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 40976EAF437D05B5
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3B4FE6ACC0B21F32