Release 1.20.1-84
Decrease forge version requirement to 47.1.3.
No functional change on Fabric.

This is to accomodate neoforge 1.20.1 users, because the Forge and NeoForge codebases
diverge after this version.
Note though that Patchouli 1.20.1 is still targeting legacy forge in 1.20.1, and reports
related to neoforge will not be accepted until 1.20.2+, where we plan to switch to targetting neoforge.