fix: prevent errors raised from accessing .graded property

This is a temporary commit, might be reverted. This commit is done to
make tests pass, so that other quality checks can run.

openedx/core/djangoapps/xblock/runtime/runtime.py

@@ -124,8 +124,8 @@ def __init__(
             id_reader=id_reader or OpaqueKeyReader(),
             mixins=(
                 LmsBlockMixin,  # Adds Non-deprecated LMS/Studio functionality
-                XBlockShim,  # Adds deprecated LMS/Studio functionality / backwards compatibility
                 InheritanceMixin,
+                XBlockShim,  # Adds deprecated LMS/Studio functionality / backwards compatibility
             ),
             default_class=None,
             select=None,