ansible-test: yamllint, check the assigment

Ensure `yamllint`'s `check_assignment()` correctly ignore the
attribute assignment. Those don't have any `.id` attribute and will
trigger an `AttributeError` exception.

See: https://github.com/ansible/ansible/pull/73322

changelogs/fragments/ansible_test_yamllint_avoid_attribute_exception.yaml

@@ -0,0 +1,3 @@
+---
+bugfixes:
+- yamllint - do not raise an ``AttributeError`` if a value is assigned to a module attribute at the top of the module.

test/lib/ansible_test/_data/sanity/yamllint/yamllinter.py

@@ -199,7 +199,7 @@ class YamlChecker:
         def check_assignment(statement, doc_types=None):
             """Check the given statement for a documentation assignment."""
             for target in statement.targets:
-                if isinstance(target, ast.Tuple):
+                if not isinstance(target, ast.Name):
                     continue
 
                 if doc_types and target.id not in doc_types: