add purge_venv to jenkinsfile for disk api

roles/storage_api/tasks/python_venv.yaml

@@ -5,6 +5,20 @@
     name: python
     state: present
 
+- name: Purge venv if asked
+  when: purge_venv | bool
+  block:
+
+  - name: Remove service
+    ansible.windows.win_service:
+      name: "{{ disk_service_name }}"
+      state: absent
+
+  - name: purge folder
+    ansible.windows.win_file:
+      path: "{{ python_venv }}"
+      state: absent
+
 - name: Create venv folder
   ansible.windows.win_file:
     path: "{{ python_venv }}"