community[patch]:Fix for get_openai_callback() return token_cost=0.0 …

…when model is gpt-4o-11-20 (#28408)

- **Description:** update MODEL_COST_PER_1K_TOKENS for new gpt-4o-11-20.
- **Issue:** with latest gpt-4o-11-20, openai callback return
token_cost=0.0
- **Dependencies:** None (just simple dict fix.)
- **Twitter handle:** I Don't Use Twitter. 
- (However..., I have a YouTube channel. Could you upload this there, by
any chance?
https://www.youtube.com/@%EA%B2%9C%EC%B0%BD%EB%B6%80%EA%B3%A0%EB%AC%B8AI%EC%9E%90%EB%AC%B8%EC%84%BC%EC%84%B8)

libs/community/langchain_community/callbacks/openai_info.py

@@ -30,10 +30,12 @@
     "gpt-4o": 0.0025,
     "gpt-4o-2024-05-13": 0.005,
     "gpt-4o-2024-08-06": 0.0025,
+    "gpt-4o-2024-11-20": 0.0025,
     # GPT-4o output
     "gpt-4o-completion": 0.01,
     "gpt-4o-2024-05-13-completion": 0.015,
     "gpt-4o-2024-08-06-completion": 0.01,
+    "gpt-4o-2024-11-20-completion": 0.01,
     # GPT-4 input
     "gpt-4": 0.03,
     "gpt-4-0314": 0.03,