Expand item input limit in mixer recipes to 9 from 4

[C0bra5]

I was trying to backport some of the oreporc changes to 2.3.0. That's when I discovered that the mixer addrecipe function has a limit of 4 item inputs. Considering the single block mixers can have up to 9 item inputs, I believe the limit should be pushed to 9 or removed entirely.

relevant files:
https://github.com/GTNewHorizons/Minetweaker-Gregtech-5-Addon/blob/febda0e1bfe20caf44f7b930a60d3c6799048b5a/src/main/java/gttweaker/mods/gregtech/machines/Mixer.java

[Dream-Master]

change stuff in code make much more sense. We slowly remove scripts and add them to code