Fix pipeline for newer register service broker

[cweibel]

Changes proposed in this pull request:

• Switch to using the newer style pipeline-tasks/register-service-broker-and-set-plan-visibility.yml, Concourse didn't seem to want to follow the symlink introduced with cloud-gov/pipeline-tasks@648a1f7
• With this also needed to replace the reference to SERVICE_ORGANIZATION_BLACKLIST with SERVICE_ORGANIZATION_DENYLIST as the older variable has been deprecated
• Part of "make them all green" pipeline maintenance: https://github.com/cloud-gov/private/issues/618

Things to check

• For any logging statements, is there any chance that they could be logging sensitive data?
• Are log statements using a logging library with a logging level set? Setting a logging level means that log statements "below" that level will not be written to the output. For example, if the logging level is set to INFO and debugging statements are written with log.debug or similar, then they won't be written to the otput, which can prevent unintentional leaks of sensitive data.

Security considerations

Returns functionality to what we had before, should not have any changes to our security footprint

[JasonTheMain]

Looks good Chris, i like denylist wording better also