Fix typo

Author: benjie

src/pages/blog/2024-08-14-exploring-true-nullability.mdx

@@ -160,7 +160,7 @@ problem. It's important to note that both the client and the server must opt-in
 to this new mode for it to take effect, otherwise the traditional execution mode
 will be used.
 
-### No-error-propogation mode
+### No-error-propagation mode
 
 The new proposal centers around the premise of allowing clients to disable the
 "error propagation" behavior discussed above.