Bump Microsoft.NET.Test.Sdk from 15.8.0 to 15.9.0#3

dependabot-preview[bot] wants to merge 1 commit intomasterblyzer/Katas:masterfrom

dependabot/nuget/Microsoft.NET.Test.Sdk-15.9.0blyzer/Katas:dependabot/nuget/Microsoft.NET.Test.Sdk-15.9.0Copy head branch name to clipboard