Fix SpawnEntityEvent list mutability

Author: Yeregorix

src/main/java/org/spongepowered/common/event/tracking/IPhaseState.java

@@ -24,7 +24,6 @@
  */
 package org.spongepowered.common.event.tracking;
 
-import com.google.common.collect.ImmutableList;
 import net.minecraft.core.BlockPos;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
@@ -372,7 +371,7 @@ default Supplier<SpawnType> getSpawnTypeForTransaction(final C context, final En
 
     default SpawnEntityEvent createSpawnEvent(final C context,
         final @Nullable GameTransaction<@NonNull ?> parent,
-        final ImmutableList<Entity> collect,
+        final List<Entity> collect,
         final Cause currentCause
     ) {
         return SpongeEventFactory.createSpawnEntityEvent(currentCause, (List) collect);

src/main/java/org/spongepowered/common/event/tracking/PhaseStateProxy.java

@@ -24,7 +24,6 @@
  */
 package org.spongepowered.common.event.tracking;
 
-import com.google.common.collect.ImmutableList;
 import net.minecraft.core.BlockPos;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
@@ -287,7 +286,7 @@ default Supplier<SpawnType> getSpawnTypeForTransaction(final Entity entityToSpaw
     }
 
     default SpawnEntityEvent createSpawnEvent(final @Nullable GameTransaction<@NonNull ?> parent,
-        final ImmutableList<Entity> collect,
+        final List<Entity> collect,
         final Cause currentCause
     ) {
         return this.getState().createSpawnEvent(this.asContext(), parent, collect, currentCause);

src/main/java/org/spongepowered/common/event/tracking/context/transaction/world/SpawnEntityTransaction.java

@@ -44,10 +44,12 @@
 import org.spongepowered.common.event.tracking.context.transaction.type.TransactionTypes;
 import org.spongepowered.common.util.PrettyPrinter;
 
+import java.util.List;
 import java.util.Optional;
 import java.util.StringJoiner;
 import java.util.function.BiConsumer;
 import java.util.function.Supplier;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 @DefaultQualifier(NonNull.class)
@@ -102,9 +104,9 @@ public Optional<SpawnEntityEvent> generateEvent(
         final @Nullable GameTransaction<@NonNull ?> parent,
         final ImmutableList<GameTransaction<SpawnEntityEvent>> gameTransactions, final Cause currentCause
     ) {
-        final ImmutableList<Entity> collect = gameTransactions.stream()
+        final List<Entity> collect = gameTransactions.stream()
             .map(transaction -> ((SpawnEntityTransaction) transaction).entityToSpawn)
-            .collect(ImmutableList.toImmutableList());
+            .collect(Collectors.toList());
         return Optional.of(context.createSpawnEvent(parent, collect, currentCause));
     }
 

src/main/java/org/spongepowered/common/event/tracking/phase/general/ExplosionState.java

@@ -24,7 +24,6 @@
  */
 package org.spongepowered.common.event.tracking.phase.general;
 
-import com.google.common.collect.ImmutableList;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.LivingEntity;
 import net.minecraft.world.level.Explosion;
@@ -100,7 +99,7 @@ public void unwind(final ExplosionContext context) {
     public SpawnEntityEvent createSpawnEvent(
         final ExplosionContext context,
         final @Nullable GameTransaction<@NonNull ?> parent,
-        final ImmutableList<Entity> collect,
+        final List<Entity> collect,
         final Cause currentCause
     ) {
         if (parent instanceof ChangeBlock) {

src/main/java/org/spongepowered/common/event/tracking/phase/packet/inventory/CloseWindowState.java

@@ -24,7 +24,6 @@
  */
 package org.spongepowered.common.event.tracking.phase.packet.inventory;
 
-import com.google.common.collect.ImmutableList;
 import net.minecraft.world.entity.Entity;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -54,7 +53,7 @@ public Supplier<SpawnType> getSpawnTypeForTransaction(final CloseWindowContext c
 
     @Override
     public SpawnEntityEvent createSpawnEvent(final CloseWindowContext context, final @Nullable GameTransaction<@NonNull ?> parent,
-            final ImmutableList<Entity> collect, final Cause currentCause) {
+            final List<Entity> collect, final Cause currentCause) {
         return SpongeEventFactory.createDropItemEventClose(currentCause, (List) collect);
     }
 }

src/main/java/org/spongepowered/common/event/tracking/phase/packet/inventory/DropInventoryState.java

@@ -24,7 +24,6 @@
  */
 package org.spongepowered.common.event.tracking.phase.packet.inventory;
 
-import com.google.common.collect.ImmutableList;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.spongepowered.api.event.Cause;
 import org.spongepowered.api.event.CauseStackManager;
@@ -55,7 +54,7 @@ public BiConsumer<CauseStackManager.StackFrame, InventoryPacketContext> getFrame
     @Override
     public SpawnEntityEvent createSpawnEvent(
         final InventoryPacketContext context, final GameTransaction<@NonNull ?> parent,
-        final ImmutableList<net.minecraft.world.entity.Entity> collect,
+        final List<net.minecraft.world.entity.Entity> collect,
         final Cause currentCause
     ) {
         return SpongeEventFactory.createDropItemEventDispense(currentCause, (List) collect);

src/main/java/org/spongepowered/common/event/tracking/phase/packet/player/PacketCommandState.java

@@ -24,7 +24,6 @@
  */
 package org.spongepowered.common.event.tracking.phase.packet.player;
 
-import com.google.common.collect.ImmutableList;
 import net.minecraft.world.entity.Entity;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.spongepowered.api.block.transaction.BlockTransactionReceipt;
@@ -83,7 +82,7 @@ public void postBlockTransactionApplication(
     @Override
     public SpawnEntityEvent createSpawnEvent(
         final PlayerCommandPhaseContext context, final GameTransaction<@NonNull ?> parent,
-        final ImmutableList<Entity> collect, final Cause currentCause
+        final List<Entity> collect, final Cause currentCause
     ) {
         final Cause newCauseWithSpawnType = Cause.builder().from(currentCause).build(
             EventContext.builder().from(currentCause.context()).add(