Make sure assignments don't get deleted when updating a course

What does this mr do?

hotfix for changing settings on courses; it would accidentally mark assignments as deleted

Actions taken to fix bug

pass assignments as hidden element in settings

Does this MR meet the acceptance criteria?

• I have added a changelog entry to reflect the significant changes I made and the bug I fixed.
• A test was created to test the bug.
• I have updated the documentation accordingly.
• I adhere to the style guide.