Speed up setup_test_instance.sh

The setup_test_instance.sh script invokes mvn install with the -Pquick profile. The purpose of this profile is to skip everything that's not essential to getting a ready to run plugin and thus have the instance start as quickly as possible.

However, the spotless operations now also seem to be executed when setup_test_instance.sh is executed. Obviously, spotless is not essential for a test cluster. Thus, we should disable spotless in the -Pquick profile.