Issue #3516239: Force enable colors in Nightwatch output

Closes #3516239

includes/include.drupalci.main.yml

@@ -1073,6 +1073,8 @@ cspell:
     # For BC these two legacy variables have to remain defined.
     DRUPAL_TEST_WEBDRIVER_HOSTNAME_LEGACY: localhost
     DRUPAL_TEST_WEBDRIVER_PORT_LEGACY: '9515'
+    # A workaround for the Nightwatch issue https://github.com/nightwatchjs/nightwatch/issues/4401
+    FORCE_COLOR: '1'
   script:
     - cd $CI_PROJECT_DIR/$_WEB_ROOT && pwd
     - *check-composer-end-code