Bump Microsoft.NET.Test.Sdk from 15.8.0 to 15.9.0 in /exercises/hamming
Bump Microsoft.NET.Test.Sdk from 15.8.0 to 15.9.0 in /exercises/hamming

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 15.8.0 to 15.9.0.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Commits](https://github.com/microsoft/vstest/compare/v15.8.0...v15.9.0)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
ErikSchierboom/xcsharp,exercism/xcsharp,exercism/xcsharp,robkeim/xcsharp,ErikSchierboom/xcsharp,robkeim/xcsharp