Bump Newtonsoft.Json in /vs/src/CodeStream.VisualStudio.UnitTests

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 9.0.1 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@9.0.1...13.0.1)

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

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

Author: dependabot[bot]

vs/src/CodeStream.VisualStudio.UnitTests/packages.config

@@ -28,7 +28,7 @@
   <package id="Moq" version="4.10.1" targetFramework="net472" />
   <package id="MSTest.TestAdapter" version="1.4.0" targetFramework="net472" />
   <package id="MSTest.TestFramework" version="1.4.0" targetFramework="net472" />
-  <package id="Newtonsoft.Json" version="9.0.1" allowedVersions="[9.0.1]" targetFramework="net472" />
+  <package id="Newtonsoft.Json" version="13.0.1" allowedVersions="[13.0.1]" targetFramework="net472" />
   <package id="System.Collections.Immutable" version="1.3.1" targetFramework="net472" />
   <package id="System.ComponentModel.Composition" version="4.5.0" targetFramework="net472" />
   <package id="System.Composition" version="1.0.31" targetFramework="net472" />