copr: let nagios_client role to install nrpe

We shouldn't install `nrpe` package in the `copr/base` playbook
because it creates the following user

    nrpe❌992:991:NRPE user for the NRPE service:/var/run/nrpe:/sbin/nologin

That UID collides with an user for keygen

    - user: name="copr-signer" group=copr-signer groups=apache uid=992

The `nrpe` installation needs to be done later, in the `nagios_client`
role that we call after `copr/keygen` role.

roles/copr/base/tasks/main.yml

@@ -49,14 +49,6 @@
   tags:
   - packages
 
-- name: install common copr packages
-  dnf:
-    state: present
-    pkg:
-      - "nrpe"
-  tags:
-  - packages
-
 - name: install dev helper packages
   dnf:
     state: present