Use Auto-DevOps and Auto-deploy for Webgoat

Our Webgoat test project is using an old and obsolete copy of auto-devops. This leads to issues like gitlab-org/security-products/tests/webgoat!13 (diffs) where some annotations are missing. As a result, the deploy board is incomplete, and doesn't provide the state of the pods during and after deploys: https://gitlab.com/gitlab-org/security-products/tests/webgoat/environments It also makes the whole config very messy and hard to maintain.

We should upgrade this configuration to remove everything that is already supported by ADO. It will also serve as a nice example for our users, since some jobs still require a few tweaks: https://gitlab.com/gitlab-org/security-products/tests/webgoat/blob/9325bb9869aa9352f0963dae848b54d6160aaef7/.gitlab-ci.yml#L117-131

@tpazitny what do you think?