fix(low-code cdk): fix set_initial_state for incremental_dependency and empty parent state (#411)

Co-authored-by: octavia-squidington-iii <[email protected]>

Author: lazebnyi

airbyte_cdk/sources/declarative/partition_routers/substream_partition_router.py

@@ -280,20 +280,15 @@ def set_initial_state(self, stream_state: StreamState) -> None:
 
         parent_state = stream_state.get("parent_state", {})
 
-        # If `parent_state` doesn't exist and at least one parent stream has an incremental dependency,
-        # copy the child state to parent streams with incremental dependencies.
-        incremental_dependency = any(
-            [parent_config.incremental_dependency for parent_config in self.parent_stream_configs]
-        )
-        if not parent_state and not incremental_dependency:
-            return
-
-        if not parent_state and incremental_dependency:
-            # Migrate child state to parent state format
-            parent_state = self._migrate_child_state_to_parent_state(stream_state)
-
         # Set state for each parent stream with an incremental dependency
         for parent_config in self.parent_stream_configs:
+            if (
+                not parent_state.get(parent_config.stream.name, {})
+                and parent_config.incremental_dependency
+            ):
+                # Migrate child state to parent state format
+                parent_state = self._migrate_child_state_to_parent_state(stream_state)
+
             if parent_config.incremental_dependency:
                 parent_config.stream.state = parent_state.get(parent_config.stream.name, {})