Docker accidentally requires selinux-policy, if you dnf remove docker, dnf will remove not only docker but selinux-policy and selinux-policy-targeted. Why is dnf doing this? Is there some way we need to mark selinux-policy to prevent this from happening. Obviously selinux-policy is a core package on the system and should not be removed.
Unfortunately, this is known bug in PackageKit. "dnf mark install selinux-policy" should help you. *** This bug has been marked as a duplicate of bug 1259865 ***