Fix directory level when computing script dependencies (istio#14452)

Author: leosarra

scripts/pr_tests.py

@@ -90,8 +90,7 @@ def get_script_dependencies_graph(path_prefix, file_suffix="test.sh"):
                         if el in script_dependencies:
                             to_add = script_dependencies[el] - checked
                             to_check.update(to_add)
-                            test_paths.update(map(lambda file_path: file_path[len(doc_file_prefix):].rsplit('/', 1)[0], to_add))
-
+                            test_paths.update(map(lambda file_path: file_path[len(doc_file_prefix):], to_add))
             elif filename == istio_go_dependency or \
                     filename.startswith(test_framework_pkg) or \
                     filename.startswith(test_framework_util) or \