Add support for GHSA identifier

What does this MR do?

Add support for GHSA identifier type. This allows analyzer to report vulnerabilities with such identifier.

What are the relevant issue numbers?

This is related to gitlab-org/gitlab#341361 (closed). Even if not directly part of the proposal, a side effect of upgrading bundler audit is the requirement to support such additional identifier.

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