Fix nested import_tasks when the parent import contains a template (#85599)

* Test nested import_tasks when the parent import contains a template

* Fix templating the parent_include.args

changelogs/fragments/85599-fix-templating-import_tasks-parent-include.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - import_tasks - fix templating parent include arguments.

lib/ansible/playbook/helpers.py

@@ -169,6 +169,7 @@ def load_list_of_tasks(ds, play, block=None, role=None, task_include=None, use_h
                         if not isinstance(parent_include, TaskInclude):
                             parent_include = parent_include._parent
                             continue
+                        parent_include.post_validate(templar=templar)
                         parent_include_dir = os.path.dirname(parent_include.args.get('_raw_params'))
                         if cumulative_path is None:
                             cumulative_path = parent_include_dir

test/integration/targets/include_import_tasks_nested/tasks/main.yml

@@ -9,3 +9,5 @@
 - assert:
     that:
       - nested_adjacent_count|int == 2
+
+- import_tasks: "{{ role_path }}/tests/main.yml"

test/integration/targets/include_import_tasks_nested/tests/main.yml

@@ -0,0 +1 @@
+- import_tasks: tests_relative.yml