Don't use 'warn: false' parameter with Ansible shell builtin.

The 'warn' parameter of Ansible 'shell' and 'command' builtin plugins
was deprecated in Ansible 2.11 and removed in Ansible 2.14. This patch
fixes 'baseos-ci.redhat-module.tier0.functional' tests that were failing
due to the use of the parameter on newer versions of Ansible.

tests/tests.yml

@@ -5,20 +5,12 @@
   pre_tasks:
   - name: Enable brewroot repository (so we have all latest packages available)
     command: dnf config-manager --set-enabled baseos-ci-tag-repository
-    args:
-      warn: false
   - name: Enable IDM module
     command: dnf module enable -y idm:DL1
-    args:
-      warn: false
   - name: Install IDM packages
     command: dnf module install -y idm:DL1/server idm:DL1/dns
-    args:
-      warn: false
   - name: Get Custodia version
     command: rpm -q --qf '%{VERSION}' custodia
-    args:
-      warn: false
     register: custodia_version
   roles:
   - role: standard-test-basic