Bump Newtonsoft.Json and NuGet.ProjectModel

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) and [NuGet.ProjectModel](https://github.com/NuGet/NuGet.Client). These dependencies needed to be updated together.

Updates `Newtonsoft.Json` from 13.0.3 to 13.0.3
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@13.0.3...13.0.3)

Updates `NuGet.ProjectModel` from 6.12.1 to 6.13.1
- [Release notes](https://github.com/NuGet/NuGet.Client/releases)
- [Commits](https://github.com/NuGet/NuGet.Client/commits)

---
updated-dependencies:
- dependency-name: Newtonsoft.Json
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: NuGet.ProjectModel
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

tools/Directory.Packages.props

@@ -3,7 +3,7 @@
   <ItemGroup>
     <PackageVersion Include="McMaster.Extensions.CommandLineUtils" Version="4.1.1" />
     <PackageVersion Include="Microsoft.Build" Version="17.12.6" />
-    <PackageVersion Include="NuGet.ProjectModel" Version="6.12.1" />
+    <PackageVersion Include="NuGet.ProjectModel" Version="6.13.1" />
     <PackageVersion Include="System.IO.Abstractions" Version="21.3.1" />
     <PackageVersion Include="Valleysoft.DockerfileModel" Version="1.2.0" />
     <PackageVersion Include="YamlDotNet" Version="16.3.0" />