I am a beginner regarding Ubuntu software, and I've got a warning that I cannot handle. Moreover, it seems that this error prevents the Ubuntu 22.04 to upgrade to the newer LTS version. Please, help me by explaining step by step what am I supposed to do since I am a novice. Below I printed the warning that I get whenever I update Ubuntu packages:
W: file:/var/cuda-repo-ubuntu2004-11-4-local/Release.gpg: Key is stored in legacy trusted.gpg keyring (/etc/apt/trusted.gpg), see the DEPRECATION section in apt-key(8) for details.
Edit: I tired the solution proposed here: Key is stored in legacy trusted.gpg keyring (/etc/apt/trusted.gpg). The problem is that now I get three warnings that seem more severe:
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://ppa.launchpadcontent.net/maarten-fonville/android-studio/ubuntu jammy InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 4EE97B1881326419 NO_PUBKEY 4DEA8909DC6A13A3
W: Failed to fetch https://ppa.launchpadcontent.net/maarten-fonville/android-studio/ubuntu/dists/jammy/InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 4EE97B1881326419 NO_PUBKEY 4DEA8909DC6A13A3
W: Some index files failed to download. They have been ignored, or old ones used instead.
Edit: I tried a solution proposed here: Nvidia GPG Error The following signatures couldn't be verified because the public key is not available: NO_PUBKEY and now I encounter this issue again:
W: file:/var/cuda-repo-ubuntu2004-11-4-local/Release.gpg: Key is stored in legacy trusted.gpg keyring (/etc/apt/trusted.gpg), see the DEPRECATION section in apt-key(8) for details.
