fix a small typo (#5120)

Co-authored-by: Ryan Sweet <[email protected]>
Co-authored-by: Eric Zhu <[email protected]>

python/packages/autogen-core/docs/src/user-guide/core-user-guide/design-patterns/group-chat.ipynb

@@ -17,7 +17,7 @@
     "In a group chat, participants take turn to publish a message, and the process\n",
     "is sequential -- only one agent is working at a time.\n",
     "Under the hood, the order of turns is maintained by a Group Chat Manager agent,\n",
-    "which selects the next agent to speak upon receving a message.\n",
+    "which selects the next agent to speak upon receiving a message.\n",
     "The exact algorithm for selecting the next agent can vary based on your\n",
     "application requirements. \n",
     "Typically, a round-robin algorithm or a selector with an LLM model is used.\n",