Fix shebang sanity test module identification.

changelogs/fragments/ansible-test-shebang-sanity.yml

@@ -0,0 +1,2 @@
+bugfixes:
+    - ansible-test - The shebang sanity test now correctly identifies modules in subdirectories in collections.

test/lib/ansible_test/_data/sanity/code-smell/shebang.py

@@ -88,7 +88,7 @@ def main():
                         'test/integration/targets/module_precedence/lib_with_extension',
                 ):
                     is_module = True
-            elif dirname == 'plugins/modules':
+            elif path.startswith('plugins/modules/'):
                 is_module = True
 
             if is_module: