[#2845] Bump Spring boot to 4.x

[avgustinmm]

Notes:

1. (!) Eclipselink shall be migrated to 5.0 (in 4.0.8 there are incompatible classes, e.g EJBQueryImpl doesn't implement some newer methods). In the moment is with beta (5.0.0-B12) - JUST for testing!
2. (!) Ethlo plugin doesn't work with Eclipselink 5.0, it builds with Eclipselink 4.0.8 (could be a problem)
3. Dependencies - new starters, test starters changes, some dependencies refactoring
4. Auto-configs split - package changes, some properties classes changes
5. Spring nullable org.springframework.lang.Nullable/NonNull are depecated and replaced with jspcify -> org.jspecify.annotations.Nullable/NonNull (NullMarked)
6. Lombok config - adding lombok.addNullAnnotations=jspecify - to do not mess annotations
7. Distributed lock table changes - SP_LOCK table db migration
8. Spring Retry replaced with Spring Core Retry - does repace retry in hawkbit
9. Specifications -> added Update/Delete(/Predicate) Specifications and JpaSpecificationExecutor changed
10. HawkbitBaseRepositoryFactoryBean modified to register properly
11. Jackson - 2 -> 3, package migrations, finals are not deserialized by default(enable finals deserialization, consider make non-final), too ‘smart’ tries to set complex objects instead of using non args constructor (-> @JsonIgnore), some other default configs made

[sonarqubecloud]

Quality Gate passed

Issues
29 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.5% Duplication on New Code

See analysis details on SonarQube Cloud