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

Fluxbox switch source
https://github.com/void-linux/void-packages/pull/36863

Description:
#### 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

#### Comments

Ran into issues with the sourceforge tar using pregenerated aclocal.m4/make files. Saw that github is getting commits here and there and the source has autogen.sh so I built from there.

There are a few file differences from the sourceforge tar. From what I can tell:

 - a `defaults.cc` generated by a makefile?
 - some `tests/` are in github that aren't in sourceforge
 - already made languages files in sourceforge
 - updated docs that aren't in sourceforge