Update LLM Caching link in Optional-Dependencies.md (#2885)

* Update LLM Caching link in Optional-Dependencies.md

Fix link to direct to the current location of the LLM Caching doc

* Update Optional-Dependencies.md

---------

Co-authored-by: Qingyun Wu <[email protected]>
Co-authored-by: Jack Gerrits <[email protected]>

website/docs/installation/Optional-Dependencies.md

@@ -9,7 +9,7 @@ the option `redis`:
 pip install "pyautogen[redis]"
 ```
 
-See [LLM Caching](Use-Cases/agent_chat.md#llm-caching) for details.
+See [LLM Caching](/docs/topics/llm-caching) for details.
 
 ## IPython Code Executor