Bump NSubstitute from 5.3.0 to 6.0.0

---
updated-dependencies:
- dependency-name: NSubstitute
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

Directory.Packages.props

@@ -39,7 +39,7 @@
     <PackageVersion Include="Vortice.Direct3D11" Version="3.6.2" />
     <PackageVersion Include="Vortice.Direct3D12" Version="3.8.3" />
     <PackageVersion Include="coverlet.msbuild" Version="6.0.4" />
-    <PackageVersion Include="NSubstitute" Version="5.3.0" />
+    <PackageVersion Include="NSubstitute" Version="6.0.0" />
     <PackageVersion Include="NSubstitute.Analyzers.CSharp" Version="1.0.17" />
     <PackageVersion Include="Shouldly" Version="4.3.0" />
     <PackageVersion Include="coverlet.collector" Version="6.0.4" />