Upgrade to Spring Boot 2.7 final OS version, plus related libraries

XM 15 and 14 are on Spring Boot 2.7.16, current latest is 2.7.18.

https://docs.spring.io/spring-boot/docs/2.7.18/reference/html/dependency-versions.html

As Spring Boot is leading for other libraries, check also those, e.g. Spring itself would go from 5.3.33 to 5.3.39.

Note that 5.3.40 exists (see here) however it cannot be used because it was published only for Enterprise clients, after Open Source support stopped for 5.3.x, see https://spring.io/projects/spring-framework#support.