سلام ممنون از پاسختون.
خروجی apt update بعد از پاک کردن docker:
Hit:1 http://mirror.hetzner.com/debian/packages bullseye InRelease
Get:2 http://mirror.hetzner.com/debian/packages bullseye-updates InRelease [44.1 kB]
Get:3 http://mirror.hetzner.com/debian/security bullseye-security InRelease [48.4 kB]
Get:4 http://archive.ubuntu.com/ubuntu xenial InRelease [247 kB]
Get:5 http://security.ubuntu.com/ubuntu xenial-security InRelease [99.8 kB]
Get:6 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [99.8 kB]
Get:7 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [97.4 kB]
Get:8 http://mirror.hetzner.com/debian/security bullseye-security/main amd64 Packages [210 kB]
Get:9 http://mirror.hetzner.com/debian/security bullseye-security/main Translation-en [137 kB]
Err:4 http://archive.ubuntu.com/ubuntu xenial InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
Err:6 http://archive.ubuntu.com/ubuntu xenial-updates InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
Err:7 http://archive.ubuntu.com/ubuntu xenial-backports InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
Err:5 http://security.ubuntu.com/ubuntu xenial-security 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://archive.ubuntu.com/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://archive.ubuntu.com/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.
W: GPG error: http://archive.ubuntu.com/ubuntu xenial-updates 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://archive.ubuntu.com/ubuntu xenial-updates 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.
W: GPG error: http://archive.ubuntu.com/ubuntu xenial-backports 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://archive.ubuntu.com/ubuntu xenial-backports 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.
W: GPG error: http://security.ubuntu.com/ubuntu xenial-security 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://security.ubuntu.com/ubuntu xenial-security 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.