Add OCI Image Annotations to ci-templates Docker images

Proposal

The purpose of this issue is to add OCI image annotations to the Secure stage Docker images.

These annotations are useful for people to manual use as well as for use by tools. For example, Snyk uses them in its UI and Renovate uses them to find release notes.

See:

• https://github.com/opencontainers/image-spec/blob/main/annotations.md#pre-defined-annotation-keys
• https://snyk.io/blog/how-and-when-to-use-docker-labels-oci-container-annotations/
• https://github.com/renovatebot/renovate/blob/34.115.1/lib/modules/datasource/docker/readme.md

Implementation Plan

1. Update the scripts/build_image.sh script in the ci-templates project to include annotations for the following fields:

   Annotation	Value
   annotation.org.opencontainers.image.revision	CI_COMMIT_SHA
   annotation.org.opencontainers.image.source	CI_PROJECT_URL
   annotation.org.opencontainers.image.url	CI_PROJECT_URL
   annotation.org.opencontainers.image.title	CI_PROJECT_TITLE
   annotation.org.opencontainers.image.vendor	GitLab

2. Test to ensure that the annotations are added as expected.

   Tested here

/cc @tkopel