"Detach" icon within Lesson settings does not actually detach lesson

### Reproduction Steps

1. In the Course Builder, click on Settings for a Lesson
2. Click on the Detach icon in the top-right of the Lesson settings panel on the right
3. Confirm you want to detach the Lesson

### Expected Behavior

The lesson is removed from the list of lessons.

### Actual Behavior

The lesson still appears to be attached, but if you click **Save Changes** the lesson does become detached. Clicking "Detach" on the left side panel (in the list of lessons/sections) will show it as detached before you save changes.