There's a closed pull request on the void-packages repository

jamulus: update to 3.9.1
https://github.com/void-linux/void-packages/pull/40204

Description:
Updated version and checksum. Built correctly and runs.

<!-- Uncomment relevant sections and delete options which are not applicable -->

#### Testing the changes
- I tested the changes in this PR: **YES**

#### Local build testing
- I built this PR locally for my native architecture, x86_64 (Glibc)