add span to data categories

Author: sentrivana

sentry_sdk/envelope.py

@@ -279,6 +279,8 @@ def data_category(self):
             return "session"
         elif ty == "attachment":
             return "attachment"
+        elif ty == "span":
+            return "span"
         elif ty == "transaction":
             return "transaction"
         elif ty == "event":