Deprecate some rarely used events for removal (#10904)

See PR description for details

src/main/java/net/minecraftforge/client/event/GatherAtlasMetadataSectionsEvent.java

@@ -13,7 +13,12 @@ import java.util.Set;
 /**
  * Fired when an Atlas is being loaded.
  * This allows you to add custom metadata sections that will be loaded from the sprite's .mcmeta file.
+ *
+ * @deprecated This event is scheduled for removal in 26.4 due to a lack of adoption by mods, in order to ease porting.
+ *             Please reach out to the Forge team if you are relying on this and would like to see it remain in Forge.
+ *             We may keep it or add it back in a future version if there is enough demand.
  */
+@Deprecated(forRemoval = true, since = "26.4")
 public final class GatherAtlasMetadataSectionsEvent extends MutableEvent {
     public static final EventBus<GatherAtlasMetadataSectionsEvent> BUS = EventBus.create(GatherAtlasMetadataSectionsEvent.class);
 
@@ -26,4 +31,4 @@ public final class GatherAtlasMetadataSectionsEvent extends MutableEvent {
     public void addType(MetadataSectionType<?> definition) {
         this.types.add(definition);
     }
-}
+}

src/main/java/net/minecraftforge/common/util/BrainBuilder.java

@@ -42,6 +42,7 @@ import org.jspecify.annotations.Nullable;
  * </ul>
  * Of course, nothing egregious will happen should a modder choose to use them for their own purposes.<br>
  */
+@Deprecated(forRemoval = true, since = "26.4")
 public class BrainBuilder<E extends LivingEntity> {
     private final Collection<MemoryModuleType<?>> memoryTypes = new HashSet<>();
     private final Collection<SensorType<? extends Sensor<? super E>>> sensorTypes = new HashSet<>();

src/main/java/net/minecraftforge/event/entity/living/LivingMakeBrainEvent.java

@@ -24,7 +24,12 @@ import net.minecraftforge.eventbus.api.event.MutableEvent;
  * and replace the previously created Brain instance for the entity.<br>
  * <br>
  * This event is fired via the {@link ForgeHooks#onLivingMakeBrain(LivingEntity, Brain, Dynamic)}.<br>
+ *
+ * @deprecated This event is scheduled for removal in 26.4 due to a lack of adoption by mods, in order to ease porting.
+ *             Please reach out to the Forge team if you are relying on this and would like to see it remain in Forge.
+ *             We may keep it or add it back in a future version if there is enough demand.
  **/
+@Deprecated(forRemoval = true, since = "26.4")
 public final class LivingMakeBrainEvent extends MutableEvent implements LivingEvent {
     public static final EventBus<LivingMakeBrainEvent> BUS = EventBus.create(LivingMakeBrainEvent.class);
 

src/main/java/net/minecraftforge/event/entity/living/LivingPackSizeEvent.java

@@ -12,6 +12,10 @@ import net.minecraftforge.eventbus.api.bus.EventBus;
 import net.minecraftforge.eventbus.api.event.MutableEvent;
 import org.jspecify.annotations.NullMarked;
 
+/// @deprecated This event is scheduled for removal in 26.4 due to a lack of adoption by mods, in order to ease porting.
+///             Please reach out to the Forge team if you are relying on this and would like to see it remain in Forge.
+///             We may keep it or add it back in a future version if there is enough demand.
+@Deprecated(forRemoval = true, since = "26.4")
 @NullMarked
 public final class LivingPackSizeEvent extends MutableEvent implements LivingEvent, HasResult {
     public static final EventBus<LivingPackSizeEvent> BUS = EventBus.create(LivingPackSizeEvent.class);

src/main/java/net/minecraftforge/event/entity/living/MonsterDisguiseEvent.java

@@ -7,14 +7,14 @@ package net.minecraftforge.event.entity.living;
 
 import net.minecraft.world.entity.monster.Monster;
 import net.minecraft.world.entity.player.Player;
-import net.minecraftforge.common.extensions.IForgeItem;
+import net.minecraftforge.common.extensions.IForgeItemStack;
 import net.minecraftforge.eventbus.api.bus.CancellableEventBus;
 import net.minecraftforge.eventbus.api.event.RecordEvent;
 import net.minecraftforge.eventbus.api.event.characteristic.Cancellable;
 
 /**
  * This event is fired on the forge bus before an Monster detects that a player is looking at them.
- * It will not be fired if the detection is already prevented by {@link IForgeItem#isEnderMask}
+ * It will not be fired if the detection is already prevented by {@link IForgeItemStack#isMonsterDisguise(Player, Monster)}
  * <p>
  * This event is {@linkplain Cancellable cancellable}.
  * If this event is cancelled, the Monster will not target the player.

src/main/java/net/minecraftforge/event/level/AlterGroundEvent.java

@@ -22,7 +22,12 @@ import org.jetbrains.annotations.ApiStatus;
  * This event is not {@linkplain Cancellable cancellable}.
  * <p>
  * This event is fired only on the {@linkplain net.minecraftforge.fml.LogicalSide#SERVER logical server}.
+ *
+ * @deprecated This event is scheduled for removal in 26.4 due to a lack of adoption by mods, in order to ease porting.
+ *             Please reach out to the Forge team if you are relying on this and would like to see it remain in Forge.
+ *             We may keep it or add it back in a future version if there is enough demand.
  */
+@Deprecated(forRemoval = true, since = "26.4")
 public final class AlterGroundEvent extends MutableEvent {
     public static final EventBus<AlterGroundEvent> BUS = EventBus.create(AlterGroundEvent.class);
 

src/main/java/net/minecraftforge/event/level/BlockFeatureGrowEvent.java

@@ -27,7 +27,12 @@ import org.jetbrains.annotations.Nullable;
  * {@linkplain Result#DENY DENY} will prevent the sapling from growing.
  * <p>
  * This event is fired only on the {@linkplain net.minecraftforge.fml.LogicalSide#SERVER logical server}.
+ *
+ * @deprecated This event is scheduled for removal in 26.4 due to a lack of adoption by mods, in order to ease porting.
+ *             Please reach out to the Forge team if you are relying on this and would like to see it remain in Forge.
+ *             We may keep it or add it back in a future version if there is enough demand.
  */
+@Deprecated(forRemoval = true, since = "26.4")
 public final class BlockFeatureGrowEvent implements LevelEvent, HasResult {
     public static final EventBus<BlockFeatureGrowEvent> BUS = EventBus.create(BlockFeatureGrowEvent.class);