Fix post-deploy mode

Ansible changed the default mode for files, even in stable
releases. [1]

This change restores the previous default (with the common
umask).

[1] https://github.com/ansible/ansible/pull/70221

Change-Id: I0f81214b4f95fe8a378844745ebc77f3c43027ab
Closes-Bug: #1891145

ansible/post-deploy.yml

@@ -7,4 +7,5 @@
       template:
         src: "roles/common/templates/admin-openrc.sh.j2"
         dest: "{{ node_config }}/admin-openrc.sh"
+        mode: 0644
       run_once: True

releasenotes/notes/bug-1891145-95e3943e8e030962.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixes ``post-deploy`` action with new Ansible releases setting a wrong mode
+    on the created file. `LP#1891145 <https://launchpad.net/bugs/1891145>`__