После проделанных действий, со страницы: https://losst.pro/kak-ispravit-key-is-s ... g-v-ubuntu
Перенос ключей в /etc/apt/trusted.gpg.d/
получилась следующая картинка:
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
/etc/apt/trusted.gpg.d/linuxmint-keyring.gpg
--------------------------------------------
pub rsa4096 2016-05-24 [SC]
302F 0738 F465 C153 5761 F965 A661 6109 451B BBF2
uid [ неизвестно ] Linux Mint Repository Signing Key <root@linuxmint.com>
sub rsa4096 2016-05-24 [E]
/etc/apt/trusted.gpg.d/ubuntu-defaults.chroot.key.gpg
-----------------------------------------------------
pub rsa4096 2016-05-24 [SC]
302F 0738 F465 C153 5761 F965 A661 6109 451B BBF2
uid [ неизвестно ] Linux Mint Repository Signing Key <root@linuxmint.com>
sub rsa4096 2016-05-24 [E]
/etc/apt/trusted.gpg.d/ubuntu-keyring-2012-cdimage.gpg
------------------------------------------------------
pub rsa4096 2012-05-11 [SC]
8439 38DF 228D 22F7 B374 2BC0 D94A A3F0 EFE2 1092
uid [ неизвестно ] Ubuntu CD Image Automatic Signing Key (2012) <cdimage@ubuntu.com>
/etc/apt/trusted.gpg.d/ubuntu-keyring-2016-dbgsym.gpg
-----------------------------------------------------
pub rsa4096 2016-03-21 [SC]
F2ED C64D C5AE E1F6 B9C6 21F0 C8CA B659 5FDF F622
uid [ неизвестно ] Ubuntu Debug Symbol Archive Automatic Signing Key (2016) <ubuntu-archive@lists.ubuntu.com>
/etc/apt/trusted.gpg.d/ubuntu-keyring-2018-archive.gpg
------------------------------------------------------
pub rsa4096 2018-09-17 [SC]
F6EC B376 2474 EDA9 D21B 7022 8719 20D1 991B C93C
uid [ неизвестно ] Ubuntu Archive Automatic Signing Key (2018) <ftpmaster@ubuntu.com>