chore(deps): Bump NSubstitute in /packages/@jsii/dotnet-runtime/src

Bumps [NSubstitute](https://github.com/nsubstitute/NSubstitute) from 5.1.0 to 5.3.0.
- [Release notes](https://github.com/nsubstitute/NSubstitute/releases)
- [Changelog](https://github.com/nsubstitute/NSubstitute/blob/main/CHANGELOG.md)
- [Commits](nsubstitute/NSubstitute@v5.1.0...v5.3.0)

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

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

packages/@jsii/Directory.Build.targets

@@ -11,7 +11,7 @@
     <PackageReference Update="Microsoft.CodeQuality.Analyzers" Version="3.3.2" />
 
     <PackageReference Update="Microsoft.NET.Test.Sdk" Version="17.11.1" />
-    <PackageReference Update="NSubstitute" Version="5.1.0" />
+    <PackageReference Update="NSubstitute" Version="5.3.0" />
     <PackageReference Update="xunit" Version="2.9.2" />
     <PackageReference Update="xunit.runner.visualstudio" Version="2.8.2" />
     <PackageReference Update="XunitXml.TestLogger" Version="3.1.17" />