Modern-style reminder accidentals are not created after percent repeats

[Nate Whetsell]

Hi there,

Thank you for all your work on LilyPond!

When using the modern accidental style, reminder accidentals seem to be created 
after unfold repeats, but not percent repeats. Here is a snippet illustrating 
this behavior:

```
\version "2.25.34"

{
  \accidentalStyle modern

  \repeat unfold 2 { cis'1 } |
  c' |

  \repeat percent 2 { cis' } |
  c' |
}
```

All the best,
Nate