Bump Newtonsoft.Json in /Alexa.NET in the nuget group

Bumps the nuget group in /Alexa.NET with 1 update: [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json).


Updates `Newtonsoft.Json` from 12.0.2 to 13.0.1
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@12.0.2...13.0.1)

---
updated-dependencies:
- dependency-name: Newtonsoft.Json
  dependency-type: direct:production
  dependency-group: nuget
...

Signed-off-by: dependabot[bot] <[email protected]>

Alexa.NET/Alexa.NET.csproj

@@ -27,7 +27,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="12.0.2" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
   </ItemGroup>