updated tasks so they are only run once

tasks/pkgs/buf.yml

@@ -1,8 +1,16 @@
 # vim: set filetype=yaml.ansible :
 ---
-- name: Add to pkg_go
-  notify:
-    - Depend go
-  changed_when: true
-  ansible.builtin.set_fact:
-    pkg_go: "{{ pkg_go + ['github.com/bufbuild/buf/cmd/buf@latest'] }}"
+- name: Add buf
+  when:
+    - buf_configured is undefined
+  block:
+    - name: Add to pkg_go
+      notify:
+        - Depend go
+      changed_when: true
+      ansible.builtin.set_fact:
+        pkg_go: "{{ pkg_go + ['github.com/bufbuild/buf/cmd/buf@latest'] }}"
+
+    - name: Set buf_configured
+      ansible.builtin.set_fact:
+        buf_configured: true