Update pre-requisites.yml

Signed-off-by: sakshiarora13 <sakshi_arora1@dell.com>

control_plane/roles/webui_grafana/tasks/pre-requisites.yml

@@ -17,6 +17,13 @@
   command: ansible-galaxy collection install "{{ item }}"
   with_items: "{{ collections_name }}"
   changed_when: false
+
+- name: Install PyYAML using pip3
+  pip:
+    name: PyYAML
+    state: present
+    executable: pip3
+    extra_args: --ignore-installed
   
 - name: Install openshift using pip3
   pip: