This did not work for me. I followed instructions at here and here and I still have the issue on Raspbian Bullseye. It looks like some sort of cache seems to be holding on since one of the steps from the links above lists the key and it indicates that it expires in 2026 (which means the update should’ve worked). Thoughts?
$ sudo apt-get update
Hit:1 http://raspbian.raspberrypi.org/raspbian bullseye InRelease
Hit:4 http://archive.raspberrypi.org/debian bullseye InRelease
Hit:3 https://packages.gitlab.com/gitlab/gitlab-ce/raspbian bullseye InRelease
Hit:2 https://packagecloud.io/ookla/speedtest-cli/debian bullseye InRelease
Get:5 https://packages.gitlab.com/gitlab/raspberry-pi2/raspbian bullseye InRelease [23.3 kB]
Err:5 https://packages.gitlab.com/gitlab/raspberry-pi2/raspbian bullseye InRelease
The following signatures were invalid: EXPKEYSIG 3F01618A51312F3F GitLab B.V. (package repository signing key) <packages@gitlab.com>
Fetched 23.3 kB in 2s (13.5 kB/s)
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://packages.gitlab.com/gitlab/raspberry-pi2/raspbian bullseye InRelease: The following signatures were invalid: EXPKEYSIG 3F01618A51312F3F GitLab B.V. (package repository signing key) <packages@gitlab.com>
W: Failed to fetch https://packages.gitlab.com/gitlab/raspberry-pi2/raspbian/dists/bullseye/InRelease The following signatures were invalid: EXPKEYSIG 3F01618A51312F3F GitLab B.V. (package repository signing key) <packages@gitlab.com>
W: Some index files failed to download. They have been ignored, or old ones used instead.
$ sudo apt-key list 3F01618A51312F3F
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
pub rsa4096 2020-03-02 [SC] [expires: 2026-02-27]
F640 3F65 44A3 8863 DAA0 B6E0 3F01 618A 5131 2F3F
uid [ unknown] GitLab B.V. (package repository signing key) <packages@gitlab.com>
sub rsa4096 2020-03-02 [E] [expires: 2026-02-27]