Kubuntu 23.04卸载Steam后执行apt update出现GPG密钥错误的解决求助

我目前在用Kubuntu 23.04，之前通过以下命令卸载了Steam：

sudo apt remove steam*
sudo apt autoremove

之后我想通过常规的系统更新命令来更新系统：

sudo apt update
sudo apt upgrade
sudo apt autoremove

但当我执行sudo apt update时，出现了GPG密钥验证失败的错误，具体输出如下：

Hit:1 http://it.archive.ubuntu.com/ubuntu lunar InRelease
Hit:2 http://it.archive.ubuntu.com/ubuntu lunar-updates InRelease
Hit:3 http://it.archive.ubuntu.com/ubuntu lunar-backports InRelease
Hit:4 https://dl.google.com/linux/chrome/deb stable InRelease
Hit:5 http://security.ubuntu.com/ubuntu lunar-security InRelease
Hit:6 https://repo.steampowered.com/steam stable InRelease
Err:6 https://repo.steampowered.com/steam stable InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F24AEA9FB05498B7
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
All packages are up to date.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://repo.steampowered.com/steam stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F24AEA9FB05498B7
W: Failed to fetch https://repo.steampowered.com/steam/dists/stable/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F24AEA9FB05498B7
W: Some index files failed to download. They have been ignored, or old ones used instead.

请问该怎么解决这个问题呢？

备注：内容来源于stack exchange，提问作者m615