The More instruments... button uses wrong arrow icons

[IoeCmcomc]

Describe the bug
The "More instruments..." button shows the upward arrow icon when instruments are not expanded and the downward arrow icon when they are expanded.

To reproduce
Steps to reproduce the behavior:

1. Open any song
2. Reduce the window width until the "More instruments..." button appears.
3. See the wrong icon

Expected behavior
The button should display the downward icon when instruments are not expanded and vice versa.

Screenshots

Additional context
This should be easy to fix. Unfortunately, I don't have time to fix this myself.

[Bentroen]

Confirmed. Only happens with high-resolution textures enabled - the arrows are swapped compared to regular textures.