我已将 Centos7 服务器升级到 Centos8，然后升级到 Almalinux 8.8。如果我运行dnf update，任何包都会出现错误。我已经删除了 yum，所以我使用 dnf。我已经尝试了dnf clean all ，但是当我进行dnf update时，问题再次出现。这是我的更新日志的最后一部分。我在尝试更新的每个包上都会遇到相同的错误！
Public key for libstdc++-8.5.0-18.el8.alma.x86_64.rpm is not installed. Failing package is: libstdc++-8.5.0-18.el8.alma.x86_64
GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-AlmaLinux
Public key for ncurses-6.1-9.20180224.el8_8.1.x86_64.rpm is not installed. Failing package is: ncurses-6.1-9.20180224.el8_8.1.x86_64
GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-AlmaLinux
Public key for ncurses-base-6.1-9.20180224.el8_8.1.noarch.rpm is not installed. Failing package is: ncurses-base-6.1-9.20180224.el8_8.1.noarch
GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-AlmaLinux
Public key for ncurses-libs-6.1-9.20180224.el8_8.1.x86_64.rpm is not installed. Failing package is: ncurses-libs-6.1-9.20180224.el8_8.1.x86_64 …