Pipeline Refactor: CloudBees core-oc

Please refactor this project to implement the new CHT pipeline patten. The new pattern handles the downloading and staging of external dependencies by replacing the prebuild.sh script with a download.json file. Developers are now able to reference dependencies stages in the project's root directory using the Docker COPY command without interacting directly with Nexus.

Tasks for each container:

1. Pull up the latest project version to be the new project root
2. Remove the prebuild.sh script
3. Create a new download.json with references external dependencies
4. Load external dependencies using the Docker COPY command
5. Submit a Merge Request

Example container:

https://dccscr.dsop.io/dsop/mongodb/mongodb-enterprise/mongodb-operator-demo-project

Documentation:

https://dccscr.dsop.io/dsop/dccscr/-/tree/master/contributor-onboarding

/ cc @humbee @jeason @sroth @Smith