Fix release_info_test

[helderjs]

Summary

Mock DockerImageBuilder in release_info_test.py so get_manfiest_list_digest returns pre-defined digests from a lookup map instead of calling skopeo against quay.io, allowing the test to run without network access, becoming isolated and deterministic.

Proof of Work

Test pass

Checklist

• Have you linked a jira ticket and/or is the ticket in the title?
• Have you checked whether your jira ticket required DOCSP changes?
• Have you added changelog file?
  • use skip-changelog label if not needed
  • refer to Changelog files and Release Notes section in CONTRIBUTING.md for more details

[github-actions]

⚠️ (this preview might not be accurate if the PR is not rebased on current master branch)

MCK 1.7.1 Release Notes

Other Changes

• Container images: Merged the init-database and init-appdb init container images into a single init-database image. The init-appdb image will no longer be published and does not affect existing deployments.
• Helm Chart: Removed operator.baseName Helm value. This value was never intended to be consumed by operator users and was never documented. The value controls the prefix for workload RBAC resource names (mongodb-kubernetes default), but changing it could break the operator and workloads because the operator is not aware of custom prefixes. With this change, the Helm chart will no longer allow customisation and the relevant resources will be deployed with predefined names (ServiceAccount with names mongodb-kubernetes-appdb, mongodb-kubernetes-database-pods, mongodb-kubernetes-ops-manager, Role with name mongodb-kubernetes-appdb and RoleBinding with name mongodb-kubernetes-appdb).