Mixin Extras NeoForge on Forge Fix

Fixes errors like 

Modules MixinExtras and mixinextras.neoforge export package com.llamalad7.mixinextras.sugar.impl.ref to module just_blahaj

and

Module mixinextras.neoforge contains package com.llamalad7.mixinextras.lib.antlr.runtime.misc, module MixinExtras exports package com.llamalad7.mixinextras.lib.antlr.runtime.misc to mixinextras.neoforge

Specifically if the error mentions BOTH MixinExtras and mixinextras.neoforge this should fix the problem.

Note this error will not appear in the latest.log on 1.18.2 and 1.19.2, and instead will only appear in launcher log files, so other symptoms that can indicate this is the log cutting off after the [net.minecraftforge.fml.loading.moddiscovery.JarInJarDependencyLocator/]: Found 3 dependencies adding them to mods collection line on versions older than 1.20.1.

This fixes the error by including an empty MixinExtras NeoForge jar, and a full MixinExtras forge jar. This ensures that only the Forge jar tries to load, preventing the error with both a full NeoForge and full Forge jar loading.

MixinExtras is licensed under the MIT license and as such is allowed to be redistributed like this: https://github.com/LlamaLad7/MixinExtras/blob/master/LICENSE

Authors who use MCreator 1.20.1 and have found that their mod causes this issue:

This issue has been fixed by the template, you should update the template to at least version 1.3, or manually apply the fix from here: https://github.com/Spectrall368/Generator-Forge-1.20.1/commit/1628b9e5f45bfbc7c8f55ca663492e9417f53209#diff-62c102e4b8953bc980b8ef09827007df7530eedbb15d39fb0443b10b403471b0