ipaclient: do not explicitely install python-simplejson

We currently install python-simplejson unconditionally.
I believe we can avoid doing so because nothing actually uses simplejson
in these scripts:

$ grep -i simplejson extraconfig/services/ipaclient.yaml
$

We do this so we do not have to conditionalize the package installation
for CentOS/RHEL 8, because there the package is called
python3-simplejson

Change-Id: I133714ecbf8fb66647cb153a39dbd5a23bf68fe9

extraconfig/services/ipaclient.yaml

@@ -55,7 +55,6 @@ outputs:
               name: "{{ item }}"
               state: present
             with_items:
-              - python-simplejson
               - ipa-client
               - ipa-admintools
               - openldap-clients