Exlude create_voronoi function from mv_grid_district dataset

The function is excluded from the dataset and implemented as a seperate
python-operator. This is only a temporary solution to prevent conflicts
while the substation module is not moved to datasets yet. The function
osmtgmod_substation is assumed to be a dependency.

src/egon/data/airflow/dags/pipeline.py

@@ -305,6 +305,7 @@
         autocommit=True,
     )
 
+
     osm_add_metadata >> substation_tables >> substation_functions
     substation_functions >> hvmv_substation_extraction
     substation_functions >> ehv_substation_extraction
@@ -341,8 +342,15 @@
     etrago_input_data >> osmtgmod_pypsa
     run_osmtgmod >> osmtgmod_substation
 
+    # create Voronoi for MV grid districts
+    create_voronoi_substation = PythonOperator(
+        task_id="create-voronoi-substations",
+        python_callable=substation.create_voronoi,
+    )
+    osmtgmod_substation >> create_voronoi_substation
+
     # MV grid districts
-    mv_grid_districts = mv_grid_districts_setup(dependencies=[osmtgmod_substation])
+    mv_grid_districts = mv_grid_districts_setup(dependencies=[create_voronoi_substation])
     mv_grid_districts.insert_into(pipeline)
     define_mv_grid_districts = tasks["mv_grid_districts.define-mv-grid-districts"]
 

src/egon/data/datasets/mv_grid_districts.py

@@ -35,7 +35,6 @@
 from egon.data.processing.substation import (
     EgonHvmvSubstation,
     EgonHvmvSubstationVoronoi,
-    create_voronoi,
 )
 
 Base = declarative_base()
@@ -775,5 +774,5 @@ def define_mv_grid_districts():
     name="MvGridDistricts",
     version="0.0.0",
     dependencies=[],
-    tasks=(create_voronoi, define_mv_grid_districts),
+    tasks=(define_mv_grid_districts),
 )