Bump Microsoft.NET.Test.Sdk from 17.9.0 to 17.10.0 in /core/getting-started/unit-testing-using-dotnet-test/PrimeService.Tests

Bump Microsoft.NET.Test.Sdk from 17.9.0 to 17.10.0 in /core/getting-started/unit-testing-using-dotnet-test/PrimeService.Tests #919