Fix incompatibility issue with Testcontainers and Docker Desktop version 4.55.

[dfcoffin]

Upgrading the Docker Desktop application to the latest version (4.55.0) causes MySQL and Postgres tests to fail. The issue is that Spring Boot 3.5 does not support Docker Desktop version 4.55.0

• Refactor pom.xml files to remove the Testcontainer dependency version, which is causing the issue, and use Spring Boot 3.5 Testcontainer dependency

[dfcoffin]

Closed by PR #45