Pin to 14-0-4 by default

What does this MR do?

As introduced with !38 (merged) we have support for producing 15-0-0 schemas. This behavior was made the default with !41 (merged), however no analyzers use v15 by default (see gitlab-org/gitlab!98587 (comment 1124056204)). If we aren't expecting that behavior to be set anywhere initially, we should keep 14-0-4 pinned by default

What are the relevant issue numbers?

N/A

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template
  • Job definition example
  • CI Templates
• Ensure the report version matches the equivalent schema version
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer