misc: chore: Remove redundant code

src/Ryujinx.Graphics.Nvdec.FFmpeg/FFmpegContext.cs

@@ -7,7 +7,7 @@ namespace Ryujinx.Graphics.Nvdec.FFmpeg
 {
     unsafe class FFmpegContext : IDisposable
     {
-        private unsafe delegate int AVCodec_decode(AVCodecContext* avctx, void* outdata, int* got_frame_ptr, AVPacket* avpkt);
+        private delegate int AVCodec_decode(AVCodecContext* avctx, void* outdata, int* got_frame_ptr, AVPacket* avpkt);
 
         private readonly AVCodec_decode _decodeFrame;
         private static readonly FFmpegApi.av_log_set_callback_callback _logFunc;

src/Ryujinx.Graphics.Nvdec.FFmpeg/Native/AVCodec.cs

@@ -17,7 +17,7 @@ namespace Ryujinx.Graphics.Nvdec.FFmpeg.Native
         public IntPtr SampleFmts;
         // Deprecated
         public unsafe ulong* ChannelLayouts;
-        public unsafe IntPtr PrivClass;
+        public IntPtr PrivClass;
         public IntPtr Profiles;
         public unsafe byte* WrapperName;
         public IntPtr ChLayouts;

src/Ryujinx.Graphics.Nvdec.FFmpeg/Native/AVCodec501.cs

@@ -17,7 +17,7 @@ namespace Ryujinx.Graphics.Nvdec.FFmpeg.Native
         public IntPtr SampleFmts;
         // Deprecated
         public unsafe ulong* ChannelLayouts;
-        public unsafe IntPtr PrivClass;
+        public IntPtr PrivClass;
         public IntPtr Profiles;
         public unsafe byte* WrapperName;
 #pragma warning restore CS0649

src/Ryujinx.Graphics.Nvdec.FFmpeg/Native/AVCodecContext.cs

@@ -6,7 +6,7 @@ namespace Ryujinx.Graphics.Nvdec.FFmpeg.Native
     struct AVCodecContext
     {
 #pragma warning disable CS0649 // Field is never assigned to
-        public unsafe IntPtr AvClass;
+        public IntPtr AvClass;
         public int LogLevelOffset;
         public int CodecType;
         public unsafe AVCodec* Codec;