Removal of CI_BUILD_* variables

What does this MR do?

A customer has asked in a ticket about what to change CI_BUILD_REF to. Link for GitLab team members.

be sure to change to the current CI_JOB_* predefined variables which are identical (except for the updated name).

CI_JOB_REF is not in

• https://docs.gitlab.com/ee/update/deprecations.html#ci_build_-predefined-variables
• https://docs.gitlab.com/ee/ci/variables/predefined_variables.html

When I went back to 12.10/13.0 I found references to CI_BUILD_REF and the mapping isn't to CI_JOB_REF.

8.x name	9.0+ name
CI_BUILD_BEFORE_SHA	CI_COMMIT_BEFORE_SHA
CI_BUILD_ID	CI_JOB_ID
CI_BUILD_MANUAL	CI_JOB_MANUAL
CI_BUILD_NAME	CI_JOB_NAME
CI_BUILD_REF **	CI_COMMIT_SHA **
CI_BUILD_REF_NAME	CI_COMMIT_REF_NAME
CI_BUILD_REF_SLUG	CI_COMMIT_REF_SLUG

Adding this table (from 12.10), in full, to the deprecation notice, and removing some dangling references to CI_BUILD_* variables.

Related issues

#352957 (closed)

Author's checklist

• Consider taking the GitLab Technical Writing Fundamentals course.
• Follow the:
  • Documentation process.
  • Documentation guidelines.
  • Style Guide.
• Ensure that the product tier badge is added to topic's h1.
• Request a review based on:
  • The documentation page's metadata.
  • The associated Technical Writer.

If you are only adding documentation, do not add any of the following labels:

• ~"frontend"
• ~"backend"
• ~"type::bug"
• ~"database"

These labels cause the MR to be added to code verification QA issues.

Review checklist

Documentation-related MRs should be reviewed by a Technical Writer for a non-blocking review, based on Documentation Guidelines and the Style Guide.

• If the content requires it, ensure the information is reviewed by a subject matter expert.
• Technical writer review items:
  • Ensure docs metadata is present and up-to-date.
  • Ensure the appropriate labels are added to this MR.
  • If relevant to this MR, ensure content topic type principles are in use, including:
    • The headings should be something you'd do a Google search for. Instead of Default behavior, say something like Default behavior when you close an issue.
    • The headings (other than the page title) should be active. Instead of Configuring GDK, say something like Configure GDK.
    • Any task steps should be written as a numbered list.
    • If the content still needs to be edited for topic types, you can create a follow-up issue with the docs-technical-debt label.
• Review by assigned maintainer, who can always request/require the reviews above. Maintainer's review can occur before or after a technical writer review.
• Ensure a release milestone is set.