Bump merge train pipeline retriable time

What does this MR do and why?

• Bump merge train pipeline retriable time

Last two merge-train jobs that synced security to canonical took over 15 minutes:

• https://ops.gitlab.net/gitlab-org/merge-train/-/jobs/20440061 => 17 minutes
• https://ops.gitlab.net/gitlab-org/merge-train/-/jobs/20439088 => 21 minutes

The 'merge_train_pipeline' retriable configuration only waits up to 15 minutes, which caused the security_release_finalize:sync_security_to_canonical job to timed out before the merge-train job could finish.

This commits bumps the retriable configuration for the merge-train to 25 minutes.

Author Check-list

• [-] Has documentation been updated?