Update update-cnb-scripts task to get latest submodule
Update update-cnb-scripts task to get latest submodule

Co-authored-by: Guillermo Kardolus <f995e5708409e0468f92322e706c77752cc6c0d4@pivotal.io>

cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci