Ensure that the value field in the exception data is always a val…

…id string before passing it to `ExceptionDetails.model_validate`.

src/seer/automation/models.py

@@ -207,6 +207,8 @@ def from_event(cls, error_event: SentryEventData):
  for entry in error_event.get("entries", []):
  if entry.get("type") == "exception":
  for exception in entry.get("data", {}).get("values", []):
+ if exception.get("value") is None:
+ exception["value"] = ""
  exceptions.append(ExceptionDetails.model_validate(exception))
  if entry.get("type") == "threads":
  for thread in entry.get("data", {}).get("values", []):