Adjust test for cached import

Author: msimacek

graalpython/com.oracle.graal.python.test/src/tests/test_imports.py

@@ -145,9 +145,6 @@ def test_imp_cached_imports():
         spec = finder.find_spec("encodings", None)
         assert spec.submodule_search_locations
 
-        spec = finder.find_spec("encodings.utf_8", None)
-        assert not spec.submodule_search_locations
-
 
 def test_import_package_all() :
     import package1