Bump Microsoft.NET.Test.Sdk from 17.12.0 to 18.3.0#21

dependabot[bot] wants to merge 1 commit intomasterledgerscope/Ledgerscope.PassiveHealthChecker:masterfrom

dependabot/nuget/Ledgerscope.PassiveHealthChecker.Tests/Microsoft.NET.Test.Sdk-18.3.0ledgerscope/Ledgerscope.PassiveHealthChecker:dependabot/nuget/Ledgerscope.PassiveHealthChecker.Tests/Microsoft.NET.Test.Sdk-18.3.0Copy head branch name to clipboard