Bump Grpc.Core.Testing in /src/Tests/Coding.Blog.UnitTests

Bumps [Grpc.Core.Testing](https://github.com/grpc/grpc) from 2.42.0 to 2.43.0.
- [Release notes](https://github.com/grpc/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](https://github.com/grpc/grpc/commits)

---
updated-dependencies:
- dependency-name: Grpc.Core.Testing
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/Tests/Coding.Blog.UnitTests/Coding.Blog.UnitTests.csproj

@@ -10,7 +10,7 @@
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 		</PackageReference>
 		<PackageReference Include="FluentAssertions" Version="6.3.0" />
-		<PackageReference Include="Grpc.Core.Testing" Version="2.42.0" />
+		<PackageReference Include="Grpc.Core.Testing" Version="2.43.0" />
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
 		<PackageReference Include="NSubstitute" Version="4.2.2" />
 		<PackageReference Include="NUnit" Version="3.13.2" />