follow symlinks while discovering valid playbooks

related: https://github.com/ansible/awx/pull/6769

Co-authored-by: Francois Herbert <francois@herbert.org.nz>

awx/main/utils/ansible.py

@@ -64,6 +64,7 @@ def could_be_playbook(project_path, dir_path, filename):
                 matched = True
                 break
     except IOError:
+        logger.exception(f'failed to open {playbook_path}')
         return None
     if not matched:
         return None