only specify __root__ with TYPE_CHECKING

hotfix for #https://git.geomar.de/digital-earth/dasf/dasf-messaging-python/-/merge_requests/35#note_37501

deprogressapi/base.py

@@ -72,7 +72,8 @@ class BaseReport(BaseModel):
         repr=False,
     )
 
-    __root__: BaseReport
+    if TYPE_CHECKING:
+        __root__: BaseReport
 
     def __init__(
         self,