made age a required argument for the -clean-deleted command

nominatim/clicmd/args.py

@@ -72,12 +72,11 @@ class NominatimArgs:
     check_database: bool
     migrate: bool
     collect_os_info: bool
-    clean_deleted: bool
+    clean_deleted: str
     analyse_indexing: bool
     target: Optional[str]
     osm_id: Optional[str]
     place_id: Optional[int]
-    age: str
 
     # Arguments to 'import'
     osm_file: List[str]