Bump Newtonsoft.Json from 6.0.8 to 13.0.1 in /BlogEngine/BlogEngine.Core

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 6.0.8 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@6.0.8...13.0.1)

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

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Author: dependabot[bot]

BlogEngine/BlogEngine.Core/packages.config

@@ -1,7 +1,7 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="DynamicQuery" version="1.0" targetFramework="net45" />
   <package id="Microsoft.Web.Xdt" version="2.1.1" targetFramework="net45" />
-  <package id="Newtonsoft.Json" version="6.0.8" targetFramework="net45" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net45" />
   <package id="NuGet.Core" version="2.8.2" targetFramework="net45" />
 </packages>