Red Hat Satellite 6 に登録されているホストで yum/dnf update が失敗し、"Problem 1: cannot install the best update candidate for package xyz" エラーメッセージが表示される

Issue

• システムで yum/dnf update が失敗し、以下のエラーが表示されます。

  Error: 
  Problem 1: cannot install the best update candidate for package libidn2-2.2.0-1.el8.x86_64
    nothing provides libunistring.so.0()(64bit) needed by libidn2-2.3.1-1.el7.x86_64
  Problem 2: cannot install the best update candidate for package perl-Devel-Size-0.81-2.el8.x86_64
    nothing provides perl(:MODULE_COMPAT_5.16.3) needed by perl-Devel-Size-0.82-3.el7.x86_64
  Problem 3: cannot install the best update candidate for package perl-Text-Template-1.51-1.el8.noarch
    nothing provides perl(:MODULE_COMPAT_5.16.3) needed by perl-Text-Template-1.59-2.el7.noarch
  Problem 4: cannot install the best update candidate for package snapd-selinux-2.47.1-1.el8.noarch
    nothing provides policycoreutils-python needed by snapd-selinux-2.51-1.el7.noarch
  Problem 5: package snapd-2.51-1.el7.x86_64 requires snapd-selinux = 2.51-1.el7, but none of the providers can be installed
    cannot install the best update candidate for package snapd-2.47.1-1.el8.x86_64
    nothing provides policycoreutils-python needed by snapd-selinux-2.51-1.el7.noarch
  Problem 6: cannot install both qpid-proton-c-0.34.0-1.el7.x86_64 and qpid-proton-c-0.28.0-3.el8.x86_64
    package python3-qpid-proton-0.28.0-3.el8.x86_64 requires qpid-proton-c(x86-64) = 0.28.0-3.el8, but none of the providers can be installed
    cannot install the best update candidate for package qpid-proton-c-0.28.0-3.el8.x86_64
    problem with installed package python3-qpid-proton-0.28.0-3.el8.x86_64
  Problem 7: package snapd-2.47.1-1.el8.x86_64 requires snap-confine(x86-64) = 2.47.1-1.el8, but none of the providers can be installed
    problem with installed package snapd-2.47.1-1.el8.x86_64
    cannot install both snap-confine-2.51-1.el7.x86_64 and snap-confine-2.47.1-1.el8.x86_64
    package snapd-2.51-1.el7.x86_64 requires snapd-selinux = 2.51-1.el7, but none of the providers can be installed
    cannot install the best update candidate for package snap-confine-2.47.1-1.el8.x86_64
    nothing provides policycoreutils-python needed by snapd-selinux-2.51-1.el7.noarch
  (try to add '--allowerasing' to command line to replace conflicting packages or '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)