Allow os_glance to run in check mode

Let role fetch config file regardless of mode. This is safe operation
to run in check mode and shouldn't affect anything.

Depends-On: https://review.opendev.org/c/openstack/openstack-ansible/+/837706
Change-Id: I5352028c967685e2b2d666fc4850afe9bf6ffd10

tasks/glance_post_install.yml

@@ -130,6 +130,7 @@
     flat: yes
   changed_when: false
   run_once: true
+  check_mode: no
   with_items: "{{ glance_core_files }}"
 
 - name: Copy common config