Editing a Template in a block theme has blocks missing

This seems like a core LifterLMS bug since the "Course Progress" (vs. "Course Progress with Button") block is not searchable even on a default theme like Twenty Twenty Four.

### Reproduction Steps

+ On a site with the Sky Pilot theme activated, go to Appearance > Editor, then go to the Single Lesson template

### Expected Behavior

+ Template loads with no errors

### Actual Behavior

+ Error that the site doesn't include support for the "llms/course-progress" block, but when you view a single lesson, it renders the course progress.

### Technical notes

The `llms/course-progress` block is loaded via the included `lifterlms-blocks` helper library/plugin. Might be the timing when the blocks JS is included or a condition of it being included in the back-end while editing a Template that is incorrect.

This issue has be recreated:
+ [ ] Locally
+ [ ] On a staging site
+ [ ] On a production website
+ [ ] With only LifterLMS and a default theme