fix: use aurora type for RDS Aurora instances (#479)

Description

Use aurora type for RDS Aurora instances

Related issue

#479 (comment 1219600036)

Examples

SE images support both types:

• registry.gitlab.com/postgres-ai/se-images/rds:15
• registry.gitlab.com/postgres-ai/se-images/aurora:15

Checklist

• MR description has been reviewed
• MR changes are functionally tested
• MR does NOT have API/CLI changes OR there are API/CLI changes and they have been reviewed & DOCS ARE ADJUSTED (reference doc, etc)
• MR does NOT have UI changes OR there are UI changes and they have been reviewed & UX IS REVIEWED

Closes #479 (closed)