WIP: Store processed gitlab-ci.yaml config

What does this MR do?

A release node is being added to gitlab-ci.yaml, and it will be actioned only if the pipeline is green. The processing of the configuration occurs at the beginning of a pipeline, and will be stored to be accessible to the code to process the release upon pipeline success.

This MR will store the parsed configuration, probably in Ci::Build.ci_builds_metadata for later processing.

Parser:

• Gitlab::Ci::YamlProcessor
• Gitlab::Ci::Config

After success hooks:

• BuildSuccessWorker

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Closes #26013 (closed)