bdd: directly call utility scripts in lib

This removes the dependency on php-symfony-dotenv for the tests.

test/bdd/environment.py

@@ -1,6 +1,7 @@
-from behave import *
 from pathlib import Path
 
+from behave import *
+
 from steps.geometry_factory import GeometryFactory
 from steps.nominatim_environment import NominatimEnvironment