Bump Newtonsoft.Json in /src/RestSharp.Serializers.NewtonsoftJson (#1930)

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 12.0.1 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@12.0.1...13.0.1)

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

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/RestSharp.Serializers.NewtonsoftJson/RestSharp.Serializers.NewtonsoftJson.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
     <ItemGroup>
-        <PackageReference Include="Newtonsoft.Json" Version="12.0.1"/>
+        <PackageReference Include="Newtonsoft.Json" Version="13.0.1"/>
     </ItemGroup>
     <ItemGroup>
         <ProjectReference Include="..\RestSharp\RestSharp.csproj"/>