Add missing EPEL definition to centos-stream.conf
    
    Also enable CRB by default
    
    ```
    ❯ rpmdistro-repoquery /home/michel/src/fedora/pagure/rpmdistro-repoquery/distros/centos-stream.conf 9 hyperfine
    CentOS Stream 9 - BaseOS                                                                                                                      22 kB/s | 6.1 kB     00:00
    CentOS Stream 9 - AppStream                                                                                                                   15 kB/s | 6.2 kB     00:00
    CentOS Stream 9 - CRB                                                                                                                        2.5 MB/s | 5.0 MB     00:02
    Extra Packages for Enterprise Linux 9 - x86_64                                                                                               160 kB/s |  26 kB     00:00
    Extra Packages for Enterprise Linux 9 - Next - x86_64                                                                                         54 kB/s |  20 kB     00:00
    hyperfine-0:1.14.0-1.el9.x86_64
    ```
    
    Signed-off-by: Michel Alexandre Salim <salimma@fedoraproject.org>