Il était inutile de toucher aux dépôts officiels.
Par contre pour ton dépôt spotify, tu aurais pu virer /etc/apt/sources.list.d/03-spotify.list et le remplacer par un /etc/apt/sources.list.d/spotify.sources contenant :
Types: deb
URIs: http://repository.spotify.com
Suites: stable
Components: non-free
Signed-By:
-----BEGIN PGP PUBLIC KEY BLOCK-----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=8BS2
-----END PGP PUBLIC KEY BLOCK-----
La clé publique est la copie du contenu de https://download.spotify.com/debian/pubkey_0D811D58.gpg
Correction fonctionnelle :
Types: deb
URIs: http://repository.spotify.com
Suites: stable
Components: non-free
Signed-By: /usr/local/share/keyrings/spotify.gpg
(ajout par PengouinPdt)