Fabric API — [1.20.1] Fabric API 0.87.0+1.20.1

— Bump version (modmuss50)
— Improve Indigo and FRAPI Test Mod (#3208) (PepperCode1)
— Make DFU error-tolerant to mod custom generator types (#3213) (qouteall)
— Make deprecated modules opt-out instead of opt-in (#3246) (modmuss, Juuz)
— Fix #3255 (#3257) (modmuss)