don't delete previewyear on dry_run

compendium_v2/routes/survey.py

@@ -305,6 +305,7 @@ def publish_survey(year) -> Any:
     except ValueError as e:
         return {'message': str(e)}, 400
 
+    if not dry_run:
         db.session.execute(delete(PreviewYear).where(PreviewYear.year == year))
 
         survey.status = SurveyStatus.published