add custom pytest collector for BDD feature files

test/bdd/test_api.py

@@ -15,7 +15,7 @@ import xml.etree.ElementTree as ET
 
 import pytest
 from pytest_bdd.parsers import re as step_parse
-from pytest_bdd import scenarios, when, given, then
+from pytest_bdd import when, given, then
 
 from nominatim_db import cli
 from nominatim_db.config import Configuration
@@ -150,4 +150,4 @@ def parse_api_json_response(api_response, fmt, num):
     return result
 
 
-scenarios('features/api')
+PYTEST_BDD_SCENARIOS = ['features/api']