common: enable crb repository on mgr hosts

This is needed in order to install `ceph-mgr-dashboard`
as it has a dependency on `python3-grpcio-tools` which comes from
crb repo.

Signed-off-by: Guillaume Abrioux <gabrioux@ibm.com>

roles/ceph-mgr/tasks/pre_requisite.yml

@@ -18,6 +18,14 @@
     - ansible_facts['os_family'] != 'RedHat'
     - ansible_facts['distribution_major_version'] | int != 7
 
+- name: enable crb repository
+  community.general.dnf_config_manager:
+    name: crb
+    state: enabled
+  when:
+    - ansible_facts['os_family'] == 'RedHat'
+    - ansible_facts['distribution_major_version'] | int == 9
+
 - name: install ceph-mgr packages on RedHat or SUSE
   package:
     name: '{{ ceph_mgr_packages }}'