import_tasks: Raise an error when applying notify

notify is not valid import_tasks attribute. Raise an error
when user specifies it.

Fixes: ansible#64935

Signed-off-by: Abhijeet Kasurde <akasurde@redhat.com>

changelogs/fragments/64935_import_tasks.yml

@@ -0,0 +1,2 @@
+bugfixes:
+- Raise an error when including notify in import tasks (https://github.com/ansible/ansible/issues/64935).

lib/ansible/playbook/task_include.py

@@ -91,6 +91,13 @@ def preprocess_data(self, ds):
                 else:
                     display.warning("Ignoring invalid attribute: %s" % k)
 
+        # VALID_INCLUDE_KEYWORDS does not contain check_mode, which is supported by import_tasks
+        if ds['action'] in ('import_tasks') and ds['notify'] is not Sentinel:
+            if C.INVALID_TASK_ATTRIBUTE_FAILED:
+                raise AnsibleParserError("'notify' is not a valid attribute for a import_tasks", obj=ds)
+            else:
+                display.warning("Ignoring invalid attribute: 'notify'")
+
         return ds
 
     def copy(self, exclude_parent=False, exclude_tasks=False):