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: https://github.com/nodejs/node/pull/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>