This is part of a series to make the UBI toolbox image to build for RHEL 10.0.

The rpm-plugin-selinux package was added by mistake to the base UBI image for RHEL 9.5. It has now been removed again, and there's no need to reinstall it in the toolbox image.

In theory, reinstalling an RPM that doesn't exist with dnf reinstall should be a NOP. However, this was causing problems for the RHEL 9.5 build, and the reference to rpm-plugin-selinux was removed to address those. Therefore, let's remove it for RHEL 10.0 also.