test: disable colorMode in test-console-group

Disable colorMode in test-console-group so that the test will succeed if
run without the test runner from the command line.

PR-URL: #30886
Reviewed-By: Shelley Vohr <codebytere@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

Author: Trott

test/parallel/test-console-group.js

@@ -23,7 +23,9 @@ function setup() {
     stderr += data;
   });
 
-  c = new Console(process.stdout, process.stderr);
+  c = new Console({ stdout: process.stdout,
+                    stderr: process.stderr,
+                    colorMode: false });
 }
 
 function teardown() {