The pgvector extension is upgraded from version 0.5.1 to version 0.6.0

## Announcement The `pgvector` extension is upgraded from version 0.5.1 to version 0.6.0\. Use this extension to store and search for vector embeddings in PostgreSQL databases. For more information, see [Configure PostgreSQL extensions](https://cloud.google.com/sql/docs/postgres/extensions). To use this version of the extension, update your instance to `[PostgreSQL version].R20240130.00_09`. For more information, see [Self-service maintenance](https://cloud.google.com/sql/docs/postgres/self-service-maintenance).