remove redundant IGuildChannel interface from ITextChannel and IVoiceChannel

src/Discord.Net.Core/Entities/Channels/ITextChannel.cs

@@ -5,7 +5,7 @@ using System.Threading.Tasks;
 
 namespace Discord
 {
-    public interface ITextChannel : IMessageChannel, IMentionable, IGuildChannel, INestedChannel
+    public interface ITextChannel : IMessageChannel, IMentionable, INestedChannel
     {
         /// <summary> Checks if the channel is NSFW. </summary>
         bool IsNsfw { get; }

src/Discord.Net.Core/Entities/Channels/IVoiceChannel.cs

@@ -3,7 +3,7 @@ using System.Threading.Tasks;
 
 namespace Discord
 {
-    public interface IVoiceChannel : IGuildChannel, IAudioChannel, INestedChannel
+    public interface IVoiceChannel : INestedChannel, IAudioChannel
     {
         /// <summary> Gets the bitrate, in bits per second, clients in this voice channel are requested to use. </summary>
         int Bitrate { get; }