nheko-nightlies flatpak remote's (GPG?) key has expired

[geekosaur]

hilfy «xmonad*hilfy-2023$» ⁅xmonad-bsa⁆ Z$ flatpak update
Looking for updates…

Info: runtime org.kde.Platform branch 6.6 is end-of-life, with reason:
   We strongly recommend moving to the latest stable version of the Platform and SDK
Info: applications using this runtime:
   im.nheko.Nheko
F: Warning: Treating remote fetch error as non-fatal since runtime/im.nheko.Nheko.Locale/x86_64/master is already installed: No such ref 'runtime/im.nheko.Nheko.Locale/x86_64/master' in remote nheko-nightlies
F: Warning: Treating remote fetch error as non-fatal since app/im.nheko.Nheko/x86_64/master is already installed: No such ref 'app/im.nheko.Nheko/x86_64/master' in remote nheko-nightlies

Nothing to do.
hilfy «xmonad*hilfy-2023$» ⁅xmonad-bsa⁆ Z$ flatpak remote-ls nheko-nightlies                
error: Unable to load summary from remote nheko-nightlies: Signature made Sat 18 Jan 2025 03:25:12 PM EST using EdDSA key ID C8D75E610773F2D9
BAD signature from "Nicolas Werner <nicolas.werner@hotmail.de>"
Primary key ID 9206AE1B231E05BB
Key expired Sun 19 Jan 2025 06:00:00 AM EST
Primary key expired Sun 19 Jan 2025 06:00:00 AM EST