Make the implementation compatible with previous Ansible versions

It looks like previous version auto convert the string into an ansible
dictionary leading to issues when explicitly making use of from_json.

Author: tobiashuste

roles/gitlab_runner/tasks/main.yml

@@ -65,7 +65,7 @@
   notify: "Restart GitLab-Runner"
   no_log: "{{ gitlab_runner_hide_sensitive_changes }}"
   vars:
-    __ignition_content: "{{ __ignition_json['content'] | b64decode }}"
+    __ignition_content: "{{ __ignition_json['content'] | b64decode | from_json }}"
   when: "not __gitlab_runner_is_initial_dryrun"
 
 - name: "Start GitLab-Runner"

roles/gitlab_runner/templates/config.toml.j2

@@ -114,7 +114,7 @@ sentry_dsn = "{{ gitlab_runner_sentry_dsn }}"
     networks = [ { uuid = "{{ runner.autoscaler_network_id }}" } ]
     security_groups = [ "{{ runner.autoscaler_security_group }}" ]
     scheduler_hints = { group = "{{ runner.autoscaler_scheduler_hint }}" }
-    user_data = '{{ __ignition_content | from_json | to_json }}'
+    user_data = '{{ __ignition_content | to_json }}'
 
   [runners.autoscaler.connector_config]
     username = "{{ runner.autoscaler_username }}"