Failure getting compat on Emacs <29. seq.2.24 signature expired in gnu elpa?

[Pierre Rouleau]

Hi,

I'm trying to install the compat package on a system running Emacs 26.3 but
it fails to verify the signature of seq-2.24
I used the package-list-packages and selected compat from gnu elpa.

On that Emacs, the `package-archives` is:

(("gnu" . "https://elpa.gnu.org/packages/";)
 ("melpa" . "https://melpa.org/packages/";)
 ("melpa-stable" . "https://stable.melpa.org/packages/";)
 ("nongnu" . "https://elpa.nongnu.org/nongnu";))

When trying to install via the package-list-packages compat *Help* buffer
'install' button,
I get:

Failed to verify signature seq-2.24.tar.sig:
No public key for 645357D2883A0966 created at 2024-03-31T05:55:14-0400
using (unknown algorithm 22)
Signature made by expired key 066DAFCB81E42C40 GNU ELPA Signing Agent
(2019) <elpasign@elpa.gnu.org>
Command output:
gpg: Signature made Sun 31 Mar 05:55:14 2024 EDT
gpg:                using RSA key C433554766D3DDC64221BFAA066DAFCB81E42C40
gpg: Good signature from "GNU ELPA Signing Agent (2019) <
elpasign@elpa.gnu.org>" [expired]
gpg: Note: This key has expired!
Primary key fingerprint: C433 5547 66D3 DDC6 4221  BFAA 066D AFCB 81E4 2C40
gpg: Signature made Sun 31 Mar 05:55:14 2024 EDT
gpg:                using EDDSA key 0327BE68D64D9A1A66859F15645357D2883A0966
gpg: Can't check signature: No public key

Has someone submitted a signed package without publishing its public key or
is this something wrong on my end?

Any suggestions?

Thanks

-- 
/Pierre