[Search] Investigate odd music.get_tempo extract

[microbit-matt-hillsdon]

get_tempo has an odd extract. I can't see any justification for the text in the stubs text so maybe we mangle it somewhere along the way.

In the DOM it's a span from a single text-typed Extract that extends to "tempo".

[microbit-matt-hillsdon]

The problem stems from Pyright:

It is far from the only docstring with this issue.

I added some logging to Pyright and it's introduced in the markdown rendering. I can't see why it would be desirable.

I don't think it makes sense to fix it in Pyright without putting in the work to merge upstream changes, which will have to be after user testing. I might try a workaround for now.