Add JSpecify nullability annotations #46587
Description
Loose ends:
- Remove varargs checkstyle suppressions
- Add nullability to
org.springframework.boot.json.JsonWriter(it's currently@NullUnmarked) - Support JSpecify for optional/mandatory actuator endpoint parameters #46593
- Check public API of modules if
@Nullableis missing - Remove suppression in graphql module once Missing @Nullable annotation on GraphiQlHandler spring-graphql#1276 is fixed
- Review
@SuppressWarnings("NullAway")suppressions