Bump Newtonsoft.Json in /test/Microsoft.OpenApi.Readers.Tests

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 12.0.3 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@12.0.3...13.0.1)

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

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

Author: dependabot[bot]

test/Microsoft.OpenApi.Readers.Tests/Microsoft.OpenApi.Readers.Tests.csproj

@@ -240,7 +240,7 @@
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.4.0" />
         <PackageReference Include="FluentAssertions" Version="5.10.0">
         </PackageReference>
-        <PackageReference Include="Newtonsoft.Json" Version="12.0.3">
+        <PackageReference Include="Newtonsoft.Json" Version="13.0.1">
         </PackageReference>
         <PackageReference Include="SharpYaml" Version="1.6.5">
         </PackageReference>

test/Microsoft.OpenApi.Readers.Tests/packages.config

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="FluentAssertions" version="4.17.0" targetFramework="net461" />
-  <package id="Newtonsoft.Json" version="10.0.3" targetFramework="net461" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net461" />
   <package id="SharpYaml" version="1.6.1" targetFramework="net461" />
   <package id="xunit" version="2.3.0" targetFramework="net461" />
   <package id="xunit.abstractions" version="2.0.1" targetFramework="net461" />