[Doc] Fix example of eagle3 (#34960)

Signed-off-by: Petr Pechman <petr.pechman@firma.seznam.cz>
Co-authored-by: Petr Pechman <petr.pechman@firma.seznam.cz>

docs/features/speculative_decoding/eagle.md

@@ -44,7 +44,7 @@ llm = LLM(
         "model": "RedHatAI/Llama-3.1-8B-Instruct-speculator.eagle3",
         "draft_tensor_parallel_size": 2,
         "num_speculative_tokens": 2,
-        "method": "eagle",
+        "method": "eagle3",
     },
 )