Upgrade apm-rabbitmq-spring tests to spring boot 3

[JonasKunz]

The apm-rabbitmq-spring seems to not be covered by dependabot currently and therefore still is on spring-boot-2. This means that spring boot 3 support of this feature is currently untested on CI.

We should

• switch to using the spring-boot-parent in a <dependencymanagement> section in order to have the dependencies properly managed and upgraded via dependabot
• Ensure that both spring boot 2 and spring boot 3 are tested and working correctly for this project