Adjust for recent adventure API changes.

api/src/main/java/com/velocitypowered/api/proxy/ProxyServer.java

@@ -17,14 +17,14 @@ import java.net.InetSocketAddress;
 import java.util.Collection;
 import java.util.Optional;
 import java.util.UUID;
-import net.kyori.adventure.audience.MultiAudience;
+import net.kyori.adventure.audience.Audience;
 import net.kyori.adventure.text.Component;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
  * Provides an interface to a Minecraft server proxy.
  */
-public interface ProxyServer extends MultiAudience {
+public interface ProxyServer extends Audience {
 
   /**
    * Retrieves the player currently connected to this proxy by their Minecraft username. The search

api/src/main/java/com/velocitypowered/api/proxy/server/RegisteredServer.java

@@ -1,18 +1,17 @@
 package com.velocitypowered.api.proxy.server;
 
 import com.velocitypowered.api.proxy.Player;
-import com.velocitypowered.api.proxy.ProxyAudience;
 import com.velocitypowered.api.proxy.messages.ChannelMessageSink;
 import java.util.Collection;
 import java.util.concurrent.CompletableFuture;
-import net.kyori.adventure.audience.MultiAudience;
+import net.kyori.adventure.audience.Audience;
 
 /**
  * Represents a server that has been registered with the proxy. The {@code Audience} associated with
  * a {@code RegisteredServer} represent all players on the server connected to this proxy and do not
  * interact with the server in any way.
  */
-public interface RegisteredServer extends ChannelMessageSink, MultiAudience {
+public interface RegisteredServer extends ChannelMessageSink, Audience {
 
   /**
    * Returns the {@link ServerInfo} for this server.

proxy/src/main/java/com/velocitypowered/proxy/VelocityServer.java

@@ -72,6 +72,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.IntFunction;
 import java.util.stream.Collectors;
 import net.kyori.adventure.audience.Audience;
+import net.kyori.adventure.audience.ForwardingAudience;
 import net.kyori.adventure.text.TextComponent;
 import net.kyori.adventure.text.TranslatableComponent;
 import net.kyori.adventure.text.serializer.gson.GsonComponentSerializer;
@@ -84,7 +85,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-public class VelocityServer implements ProxyServer {
+public class VelocityServer implements ProxyServer, ForwardingAudience {
 
   private static final Logger logger = LogManager.getLogger(VelocityServer.class);
   public static final Gson GENERAL_GSON = new GsonBuilder()

proxy/src/main/java/com/velocitypowered/proxy/server/VelocityRegisteredServer.java

@@ -38,11 +38,12 @@ import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
 import net.kyori.adventure.audience.Audience;
+import net.kyori.adventure.audience.ForwardingAudience;
 import net.kyori.adventure.text.Component;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-public class VelocityRegisteredServer implements RegisteredServer {
+public class VelocityRegisteredServer implements RegisteredServer, ForwardingAudience {
 
   private final @Nullable VelocityServer server;
   private final ServerInfo serverInfo;