patch: remove usage of llm, chat model __call__ (#20788)

- `llm(prompt)` -> `llm.invoke(prompt)`
- `llm(prompt=prompt` -> `llm.invoke(prompt)` (same with `messages=`)
- `llm(prompt, callbacks=callbacks)` -> `llm.invoke(prompt,
config={"callbacks": callbacks})`
- `llm(prompt, **kwargs)` -> `llm.invoke(prompt, **kwargs)`

libs/community/tests/integration_tests/llms/test_konko.py

@@ -15,7 +15,7 @@ def test_konko_call() -> None:
         temperature=0.2,
         max_tokens=250,
     )
-    output = llm("Say foo:")
+    output = llm.invoke("Say foo:")
 
     assert llm._llm_type == "konko"
     assert isinstance(output, str)