keycloak_authentication: fix TypeError when flow has no authenticationExecutions (#11548)

* TIAAS-12174: fix(keycloak_authentication): handle None authenticationExecutions

When a flow is defined without authenticationExecutions, module.params.get()
returns None but the key still exists in the config dict. The 'in' check
passes but iterating over None raises TypeError.

Guard the iteration with an explicit None check.

* keycloak_authentication: add changelog fragment for NoneType fix

* keycloak_authentication: update changelog fragment with PR link

* Update plugins/modules/keycloak_authentication.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Changelog polishing

---------

Co-authored-by: Ivan Kokalovic <ivan.kokalovic@example.com>
Co-authored-by: Felix Fontein <felix@fontein.de>

changelogs/fragments/keycloak-authentication-none-executions.yml

@@ -0,0 +1,5 @@
+bugfixes:
+  - keycloak_authentication - fix ``TypeError`` crash when a flow is defined without
+    ``authenticationExecutions``
+    (https://github.com/ansible-collections/community.general/issues/11547,
+    https://github.com/ansible-collections/community.general/pull/11548).

plugins/modules/keycloak_authentication.py

@@ -273,7 +273,7 @@ def create_or_update_executions(kc, config, realm="master"):
         after = ""
         before = ""
         execution = None
-        if "authenticationExecutions" in config:
+        if config.get("authenticationExecutions") is not None:
             # Get existing executions on the Keycloak server for this alias
             existing_executions = kc.get_executions_representation(config, realm=realm)
             for new_exec_index, new_exec in enumerate(config["authenticationExecutions"], start=0):