Bump Newtonsoft.Json from 12.0.3 to 13.0.2 in /Gu.Units.Json.Tests

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 12.0.3 to 13.0.2.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@12.0.3...13.0.2)

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

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

Gu.Units.Json.Tests/Gu.Units.Json.Tests.csproj

@@ -22,7 +22,7 @@
     <PackageReference Include="IDisposableAnalyzers" Version="4.0.2" PrivateAssets="all" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.5.0" />
     <PackageReference Include="Microsoft.VisualStudio.Threading.Analyzers" Version="17.5.22" PrivateAssets="all" />
-    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="NUnit" Version="3.13.3" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.4.2" />
     <PackageReference Include="ReflectionAnalyzers" Version="0.3.1" PrivateAssets="all" />

Gu.Units.Json/Gu.Units.Json.csproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>net45;netstandard2.0</TargetFrameworks>
@@ -54,7 +54,7 @@
     <PackageReference Include="Microsoft.CodeAnalysis.PublicApiAnalyzers" Version="3.3.4" PrivateAssets="all" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="all" />
     <PackageReference Include="Microsoft.VisualStudio.Threading.Analyzers" Version="17.5.22" PrivateAssets="all" />
-    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="PropertyChangedAnalyzers" Version="4.0.0" PrivateAssets="all" />
     <PackageReference Include="ReflectionAnalyzers" Version="0.3.1" PrivateAssets="all" />
     <PackageReference Include="StyleCop.Analyzers" Version="1.2.0-beta.435" PrivateAssets="all" />