Bump Newtonsoft.Json in /src/Owin.Security.Providers.WordPress

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 8.0.3 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](https://github.com/JamesNK/Newtonsoft.Json/compare/8.0.3...13.0.1)

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

Signed-off-by: dependabot[bot] <support@github.com>

src/Owin.Security.Providers.WordPress/packages.config

@@ -2,6 +2,6 @@
 <packages>
   <package id="Microsoft.Owin" version="3.0.1" targetFramework="net45" />
   <package id="Microsoft.Owin.Security" version="3.0.1" targetFramework="net45" />
-  <package id="Newtonsoft.Json" version="8.0.3" targetFramework="net45" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net45" />
   <package id="Owin" version="1.0" targetFramework="net45" />
 </packages>