Finish converting all events to jspecify annotations

patches/api/Brigadier-based-command-API.patch

@@ -141,7 +141,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +@NullMarked
 +public class AsyncPlayerSendCommandsEvent<S extends CommandSourceStack> extends PlayerEvent {
 +
-+    private static final HandlerList handlers = new HandlerList();
++    private static final HandlerList HANDLER_LIST = new HandlerList();
 +    private final RootCommandNode<S> node;
 +    private final boolean hasFiredAsync;
 +
@@ -170,12 +170,13 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +        return this.hasFiredAsync;
 +    }
 +
++    @Override
 +    public HandlerList getHandlers() {
-+        return handlers;
++        return HANDLER_LIST;
 +    }
 +
 +    public static HandlerList getHandlerList() {
-+        return handlers;
++        return HANDLER_LIST;
 +    }
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/event/brigadier/AsyncPlayerSendSuggestionsEvent.java b/src/main/java/com/destroystokyo/paper/event/brigadier/AsyncPlayerSendSuggestionsEvent.java
@@ -203,7 +204,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +@NullMarked
 +public class AsyncPlayerSendSuggestionsEvent extends PlayerEvent implements Cancellable {
 +
-+    private static final HandlerList handlers = new HandlerList();
++    private static final HandlerList HANDLER_LIST = new HandlerList();
 +    private boolean cancelled = false;
 +
 +    private Suggestions suggestions;
@@ -260,12 +261,13 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +        this.cancelled = cancel;
 +    }
 +
++    @Override
 +    public HandlerList getHandlers() {
-+        return handlers;
++        return HANDLER_LIST;
 +    }
 +
 +    public static HandlerList getHandlerList() {
-+        return handlers;
++        return HANDLER_LIST;
 +    }
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/event/brigadier/CommandRegisteredEvent.java b/src/main/java/com/destroystokyo/paper/event/brigadier/CommandRegisteredEvent.java