doc/userguide: remove example with CentOS 7

CentOS 7 is EOL.

Ticket: #7749

doc/userguide/install/rpm.rst

@@ -17,28 +17,22 @@ Installing From Package Repositories
 .. note:: Instructions in the following sections require ``sudo`` to
           be installed.
 
+Enterprise Linux and Rebuilds
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 .. code-block:: none
 
    sudo dnf install epel-release dnf-plugins-core
-   sudo dnf copr enable @oisf/suricata-7.0
+   sudo dnf copr enable @oisf/suricata-8.0
    sudo dnf install suricata
 
-CentOS 7
-^^^^^^^^
-
-.. code-block:: none
-
-   sudo yum install epel-release yum-plugin-copr
-   sudo yum copr enable @oisf/suricata-7.0
-   sudo yum install suricata
-
 Fedora
 ^^^^^^
 
 .. code-block:: none
 
     sudo dnf install dnf-plugins-core
-    sudo dnf copr enable @oisf/suricata-7.0
+    sudo dnf copr enable @oisf/suricata-8.0
     sudo dnf install suricata
 
 Additional Notes for RPM Installations