(build) fix now the docker images for artifact tests

Author: arturcic

.gitignore

@@ -129,3 +129,4 @@ src/GitVersionRubyGem/bin/LibGit2Sharp.dll.config
 config.wyam.dll
 config.wyam.hash
 config.wyam.packages.xml
+/test/build

build/utils/docker.cake

@@ -101,10 +101,7 @@ void DockerTestArtifact(DockerImage dockerImage, BuildParameters parameters, str
     Information("Docker tag: {0}", tag);
     Information("Docker cmd: {0}", cmd);
 
-    if (os == "windows" && targetframework == parameters.CoreFxVersion31)
-    {
-        cmd = "-Command " + cmd; // powershell 7 needs a -Command parameter
-    }
+    cmd = "-Command " + cmd; // powershell 7 needs a -Command parameter
 
     DockerTestRun(settings, parameters, tag, "pwsh", cmd);
 }