fix idempotency for command

tasks/setup.yml

@@ -7,8 +7,14 @@
       with_items:
         - python36
 
+    - name: Check for installed pip3
+      stat:
+        path: /usr/local/bin/pip3.6
+      register: __python3_pip
+
     - name: Setup pip3
       command: /bin/python3.6 -m ensurepip
+      changed_when: __python3_pip.stat.exists
 
     - name: Link binaries to '__python3_link_bin_path'
       file: