Re-add removal of ZAP target ping

What does this MR do?

Un-reverts the removal of the ZAP target ping. This will be safe to do once the https://gitlab.com/gitlab-org/security-products/tests/dast-e2e repository has been updated to scan WebGoat correctly.

What are the relevant issue numbers?

gitlab-org/gitlab#257963 (closed)

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
  • Job definition example
  • Vendored CI Templates (also in CE)
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer