Bump Newtonsoft.Json in /src/Umbraco.Forms.Integrations.TestSite

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 12.0.1 to 13.0.2.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@12.0.1...13.0.2)

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

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

Author: dependabot[bot]

src/Umbraco.Forms.Integrations.TestSite/packages.config

@@ -41,7 +41,7 @@
   <package id="MiniProfiler" version="4.0.138" targetFramework="net472" />
   <package id="MiniProfiler.Shared" version="4.0.138" targetFramework="net472" />
   <package id="MSBuild.Umbraco.Packaging" version="1.0.2" targetFramework="net472" />
-  <package id="Newtonsoft.Json" version="12.0.1" targetFramework="net472" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net472" />
   <package id="NPoco" version="3.9.4" targetFramework="net472" />
   <package id="Owin" version="1.0" targetFramework="net472" />
   <package id="Semver" version="2.0.4" targetFramework="net472" />