Add spring support policy for spring sdk

[felix-mueller]

Add spring support policy for spring sdk here: https://docs.camunda.io/docs/next/apis-tools/spring-zeebe-sdk/getting-started/#version-compatibility

https://camunda.slack.com/archives/C037W9NMATG/p1721203971434809

"For new minor releases we usually automatically update to new minor releases of our dependencies when they are released. This general rule also applies to spring. Thus, on main (8.6) we are already on spring boot 3.3.1"

[akeller]

@christinaausley, it looks like this stemmed from a support ticket Josh took on. Can you have a look at the description and see if there is enough for you to take action? If you have questions, please follow up with the team via the Slack link.

[christinaausley]

This has been merged -- closing.