Fixing typo in comment (#28882)

Summary:
I was reading the code and noticed the typo.

## Changelog

Doesn't affect the code.

[General] [Fixed] - Message
Pull Request resolved: https://github.com/facebook/react-native/pull/28882

Differential Revision: D21529436

Pulled By: shergin

fbshipit-source-id: 82929a6f1fe7b5510ee17fff547aae9d5125891c

ReactCommon/runtimeexecutor/ReactCommon/RuntimeExecutor.h

@@ -48,7 +48,7 @@ inline static void executeAsynchronously(
  * Executes a `callback` in a *synchronous* manner using given
  * `RuntimeExecutor`.
  * Use this method when the caller needs to *be blocked* by executing the
- * callback but does not concerted about the particular thread on which the
+ * callback but does not concerned about the particular thread on which the
  * `callback` will be executed.
  */
 inline static void executeSynchronously_CAN_DEADLOCK(