fix(backend): fallback to sqlite database during test execution

backend/config/settings.py

@@ -11,6 +11,7 @@ https://docs.djangoproject.com/en/6.0/ref/settings/
 """
 
 import os
+import sys
 from pathlib import Path
 from dotenv import load_dotenv
 
@@ -87,7 +88,9 @@ WSGI_APPLICATION = 'config.wsgi.application'
 # https://docs.djangoproject.com/en/6.0/ref/settings/#databases
 
 POSTGRES_DB = os.getenv('POSTGRES_DB')
-if POSTGRES_DB:
+TESTING = 'test' in sys.argv or os.getenv('TESTING', 'False').lower() in ('true', '1', 't')
+
+if POSTGRES_DB and not TESTING:
     DATABASES = {
         'default': {
             'ENGINE': 'django.db.backends.postgresql',