Fix CI & update versions

Changes:

• use Docker image from Harbor registry instead of internal GitLab Dependency Proxy in the Kaniko build step
• use debian:stable-slim (currently Bookworm) image instead of debian:bullseye-slim
• remove reference to SubApp-related Docker image target (probably copy&paste bug)
• update Rosetta SDK version to 8.2 (prev. 7.3)

Changed files:

• /gitlab-ci/Dockerfile
• /.gitlab-ci.yml