[3dprinter-general] yagv is marked for autoremoval from testing

[Gregor Riepl]

> yagv 0.4~20171211.r234ef16+dfsg-1 is marked for autoremoval from testing on 2020-03-04
> 
> It (build-)depends on packages with these RC bugs:
> 937445: pyglet: Python2 removal in sid/bullseye
> 937507: pypng: Python2 removal in sid/bullseye

Upstream seems to be dead.
No response to https://github.com/jonathanwin/yagv/issues/20 and
https://github.com/jonathanwin/yagv/issues/15 may indicate a DFSG violation.

There is a Python 3 compatibility patch available, however:
https://github.com/jonathanwin/yagv/pull/23