updated tasks so they are only run once

tasks/pkgs/python3.yml

@@ -1,5 +1,17 @@
 # vim: set filetype=yaml.ansible :
 ---
-- name: Append to pkgs
-  ansible.builtin.set_fact:
-    pkg_sys: "{{ pkg_sys + python3.pkgs }}"
+- name: Add python3
+  when:
+    - python3_configured is undefined
+  block:
+    - name: Load python3 config
+      ansible.builtin.include_tasks:
+        file: config/python3.yml
+
+    - name: Append to pkgs
+      ansible.builtin.set_fact:
+        pkg_sys: "{{ pkg_sys + python3.pkgs }}"
+
+    - name: Set python3_configured
+      ansible.builtin.set_fact:
+        python3_configured: true