Expose project visibility as CI variable

Description

Auto DevOps (and Auto Deploy) uses CI_JOB_TOKEN for credentials to allow k8s to read images for deployments, but it does this even for public projects. We should expose the project visibility as a predefined CI variable so that Auto DevOps can skip secret creation and usage for public projects.

Proposal

Expose CI_PROJECT_VISIBILITY with values of public, internal, and private.

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Documentation blurb

Overview

What is it? Why should someone use this feature? What is the underlying (business) problem? How do you use this feature?

Use cases

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Feature checklist

Make sure these are completed before closing the issue, with a link to the relevant commit.

• Feature assurance
• Documentation
• Added to features.yml