that has been fixed already

src/main/java/carpet/mixins/ClientPlayNetworkHandler_smoothClientAnimationsMixin.java

@@ -1,52 +0,0 @@
-package carpet.mixins;
-
-import carpet.CarpetSettings;
-import net.minecraft.block.BlockState;
-import net.minecraft.block.Blocks;
-import net.minecraft.block.entity.BlockEntity;
-import net.minecraft.block.entity.PistonBlockEntity;
-import net.minecraft.client.network.ClientPlayNetworkHandler;
-import net.minecraft.network.packet.s2c.play.ChunkDataS2CPacket;
-import net.minecraft.client.world.ClientWorld;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.util.math.BlockPos;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Shadow;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
-import org.spongepowered.asm.mixin.injection.callback.LocalCapture;
-
-import java.util.Iterator;
-
-@Mixin(ClientPlayNetworkHandler.class)
-public class ClientPlayNetworkHandler_smoothClientAnimationsMixin
-{
-    @Shadow private ClientWorld world;
-    // fix as suggested by G4me4u
-    @Inject( method = "onChunkData", locals = LocalCapture.CAPTURE_FAILHARD, require = 0, at = @At(
-            value = "INVOKE",
-            target = "Lnet/minecraft/client/world/ClientWorld;getBlockEntity(Lnet/minecraft/util/math/BlockPos;)Lnet/minecraft/block/entity/BlockEntity;",
-            shift = At.Shift.AFTER
-    ))
-    private void recreateMovingPistons(ChunkDataS2CPacket packet, CallbackInfo ci,
-                                       //int i, int j, BiomeArray biomeArray, WorldChunk worldChunk,
-                                       Iterator var5, CompoundTag tag, BlockPos blockPos)
-    {
-        if (CarpetSettings.smoothClientAnimations)
-        {
-            BlockEntity blockEntity = world.getBlockEntity(blockPos);
-            if (blockEntity == null && "minecraft:piston".equals(tag.getString("id")))
-            {
-                BlockState blockState = world.getBlockState(blockPos);
-                if (blockState.getBlock() == Blocks.MOVING_PISTON) {
-                    tag.putFloat("progress", Math.min(tag.getFloat("progress") + 0.5F, 1.0F));
-                    blockEntity = new PistonBlockEntity();
-                    blockEntity.fromTag(blockState, tag);
-                    world.setBlockEntity(blockPos, blockEntity);
-                    blockEntity.resetBlock();
-                }
-            }
-        }
-    }
-}

src/main/resources/carpet.mixins.json

@@ -194,7 +194,6 @@
     "InGameHudMixin",
     "PlayerListHudMixin",
     "PistonBlockEntityRenderer_movableTEMixin",
-    "ClientPlayNetworkHandler_smoothClientAnimationsMixin",
     "ClientPlayerEntity_clientCommandMixin",
     "WorldRenderer_fogOffMixin",
     "WorldRenderer_creativeNoClipMixin",