GameRulesIntRuleAccessor doesn't use method name prefixes, and IntGameRule has a getValue method now, so the new @Overwrite requirement results in an error:

Caused by: org.spongepowered.asm.mixin.transformer.throwables.InvalidMixinException: getValue()I in fabric-game-rule-api-v1.mixins.json:GameRulesIntRuleAccessor from mod fabric-game-rule-api-v1 cannot overwrite method in net.minecraft.world.GameRules$IntGameRule because @overwrite is required by the parent configuration [ -> ACCESSOR Applicator Phase -> fabric-game-rule-api-v1.mixins.json:GameRulesIntRuleAccessor from mod fabric-game-rule-api-v1 -> Apply Accessors]

I get this error in one of my mods that uses GameRuleRegistry::register

this is mappings-dependent, but the accessor isn't required anymore