Initial kaniko based build image

What does this MR do?

Creates an image for the build stage of AutoDevOps so we can build and test this stage separately from gitlab-ce.

What are the relevant issue numbers?

• https://gitlab.com/gitlab-org/gitlab-ce/issues/50313

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has ~"Requires e2e tests" label. See the Test Planning Process.
• Security reports checked/validated by reviewer