Make behat/mink requirement in line with core
requested to merge Lendude/drupal-test-traits:make-behat-mink-compatible-with-drupal-core into master
Core has moved to behat/mink 1.8.1, see https://www.drupal.org/node/3078671
DTT pins this to 1.8.0, so there are problems installing on the 8.9.x (and 8.8.x if it gets backported). DTT should probably follow Drupal core here and set the requirement to ^1.8 instead of pinning to 1.8.0