graphics/fractgen: Update 3.0.5 => 3.0.6

Changelog:
https://github.com/dreibh/fractgen/blob/fractgen-3.0.6/ChangeLog

Commit log:
https://github.com/dreibh/fractgen/compare/fractgen-3.0.5...fractgen-3.0.6

While here remove unused dependency - doesn't link this libGL.

PR: 289765