[refactoring] when converting a project to Spring Boot 3, always use the latest 3.0.x version

[martinlippert]

When we convert a project to use Spring Boot 3 using the recipes from OpenRewrite, we need to make sure that we always convert the project to the latest 3.0.x version and that we don't need to ship a new tooling version for patch releases.

A new minor release (3.1.x) might be different though.

[BoykoAlex]

Tried changing this now. Looks like recipes don't support newVersion: 3.0.x-SNAPSHOT. Instead the recipe supports: newVersion: 3.0.x. Therefore, we'd have to wait for Boot 3 to be released and then can switch 3.0.x in the recipe.

[BoykoAlex]

Should be fixed with 61d6d1d