Fix Amiibo hanging since .NET 6 changes (#2890)

The .NET 6 changes ended up causing a difference in the way we deserialise and would end up deserializing wrongly.

This commit fixes it by resoring previous behaviour while still fixing the illink warning that caused that change in the first place

Ryujinx.HLE/HOS/Services/Nfc/Nfp/VirtualAmiibo.cs

@@ -1,6 +1,5 @@
 using Ryujinx.Common.Configuration;
 using Ryujinx.Common.Memory;
-using Ryujinx.Common.Utilities;
 using Ryujinx.HLE.HOS.Services.Mii;
 using Ryujinx.HLE.HOS.Services.Mii.Types;
 using Ryujinx.HLE.HOS.Services.Nfc.Nfp.NfpManager;
@@ -173,7 +172,7 @@ namespace Ryujinx.HLE.HOS.Services.Nfc.Nfp
 
             if (File.Exists(filePath))
             {
-                virtualAmiiboFile = JsonHelper.DeserializeFromFile<VirtualAmiiboFile>(filePath);
+                virtualAmiiboFile = JsonSerializer.Deserialize<VirtualAmiiboFile>(File.ReadAllText(filePath), new JsonSerializerOptions(JsonSerializerDefaults.General));
             }
             else
             {