Trace context is required for transactions (#11456)

* Trace context is required for transactions

* Update develop-docs/sdk/event-payloads/contexts.mdx

* Update develop-docs/sdk/event-payloads/contexts.mdx

Co-authored-by: Anton Pirker <[email protected]>

---------

Co-authored-by: Anton Pirker <[email protected]>

Author: adinauer

develop-docs/sdk/data-model/event-payloads/contexts.mdx

@@ -618,7 +618,7 @@ The following example illustrates the contexts part of the <Link to="/sdk/data-m
 
 ## Trace Context
 
-Additional information that allows Sentry to connect multiple transactions, spans, and/or errors into one trace.
+Additional information that allows Sentry to connect multiple transactions, spans, and/or errors into one trace. **Important:** If the trace context is missing, relay will drop the transaction. 
 
 `trace_id`