fix: do not import superset_config on tests (#11193)

* Do not import superset_config on tests

* Use strtobool

superset/utils/core.py

@@ -31,6 +31,7 @@ import traceback
 import uuid
 import zlib
 from datetime import date, datetime, time, timedelta
+from distutils.util import strtobool
 from email.mime.application import MIMEApplication
 from email.mime.image import MIMEImage
 from email.mime.multipart import MIMEMultipart
@@ -1564,3 +1565,7 @@ class AdhocMetricExpressionType(str, Enum):
 class RowLevelSecurityFilterType(str, Enum):
     REGULAR = "Regular"
     BASE = "Base"
+
+
+def is_test() -> bool:
+    return strtobool(os.environ.get("SUPERSET_TESTENV", "false"))