add project_root to debug_meta in event

Author: lobsterkatie

sentry_sdk/client.py

@@ -541,6 +541,10 @@ def _prepare_event(
         if event.get("platform") is None:
             event["platform"] = "python"
 
+        event.setdefault("debug_meta", {}).update(
+            {"project_root": self.options["project_root"]}
+        )
+
         event = handle_in_app(
             event,
             self.options["in_app_exclude"],