Update the Oracle docker image version used for test and integration to use Oracle Database 23ai Free

Oracle recently released Oracle Database 23ai Free, specifically version 23.4, as their latest free database version.

We should update our testing infrastructure to utilize this free version, using the Docker image available at[ |https://github.com/gvenzl/oci-oracle-free] https://github.com/gvenzl/oci-oracle-free

This repository is known for being a reliable and well-maintained source for Oracle Database images.