Remove the / in a test that would fail because paths in linux are different than win

Author: nagilson

src/Tests/Microsoft.NET.Publish.Tests/GivenThatWeWantToPublishAHelloWorldProject.cs

@@ -444,7 +444,7 @@ public void It_publishes_on_release_if_PublishRelease_property_set(bool optedOut
                .CopyTestAsset("HelloWorld", $"{optedOut}")
                .WithSource();
 
-            File.WriteAllText(Path.Combine(helloWorldAsset.Path, "/Directory.Build.props"), "<Project><PropertyGroup><PublishRelease>true</PublishRelease></PropertyGroup></Project>");
+            File.WriteAllText(Path.Combine(helloWorldAsset.Path, "Directory.Build.props"), "<Project><PropertyGroup><PublishRelease>true</PublishRelease></PropertyGroup></Project>");
 
             new DotnetPublishCommand(Log, helloWorldAsset.TestRoot)
                 .WithEnvironmentVariable(EnvironmentVariableNames.DISABLE_PUBLISH_AND_PACK_RELEASE, optedOut.ToString())