fix: null return hints

DisCatSharp.Lavalink/LavalinkGuildPlayer.cs

@@ -660,7 +660,7 @@ public void AddToQueue(LavalinkPlaylist playlist)
 	/// </summary>
 	/// <param name="track">The next track in the queue, or null if the queue is empty.</param>
 	/// <returns>True if a track was found, false otherwise.</returns>
-	public bool TryPeekQueue(out LavalinkTrack? track)
+	public bool TryPeekQueue([NotNullWhen(true)] out LavalinkTrack? track)
 	{
 		if (QueueInternal.TryGetValue(this.GuildId, out var queue) && queue.TryPeek(out var result))
 		{

DisCatSharp.Lavalink/LavalinkQueue.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 
 namespace DisCatSharp.Lavalink;
 
@@ -115,7 +116,7 @@ public bool TryDequeue(out T value)
 	///     <see langword="true" /> if there is an object at the beginning of the <see cref="LavalinkQueue{T}" />;
 	///     otherwise, <see langword="false" />.
 	/// </returns>
-	public bool TryPeek(out T value)
+	public bool TryPeek([NotNullWhen(true)] out T? value)
 	{
 		lock (this._list)
 		{
@@ -125,7 +126,7 @@ public bool TryPeek(out T value)
 				return false;
 			}
 
-			value = this._list.First.Value;
+			value = this._list.First.Value!;
 			return true;
 		}
 	}