add an manual AT to CommandNode for now

paper-server/patches/sources/com/mojang/brigadier/tree/CommandNode.java.patch

@@ -1,6 +1,12 @@
 --- a/com/mojang/brigadier/tree/CommandNode.java
 +++ b/com/mojang/brigadier/tree/CommandNode.java
-@@ -32,6 +_,16 @@
+@@ -27,11 +_,21 @@
+     private final Map<String, CommandNode<S>> children = new LinkedHashMap<>();
+     private final Map<String, LiteralCommandNode<S>> literals = new LinkedHashMap<>();
+     private final Map<String, ArgumentCommandNode<S, ?>> arguments = new LinkedHashMap<>();
+-    private final Predicate<S> requirement;
++    public final Predicate<S> requirement; // Paper
+     private final CommandNode<S> redirect;
      private final RedirectModifier<S> modifier;
      private final boolean forks;
      private Command<S> command;