[Docs] Spec decoding docs warning removal (#34439)

Signed-off-by: NickLucche <nlucches@redhat.com>

docs/features/spec_decode/README.md

 # Speculative Decoding
 
-!!! warning
-    Please note that speculative decoding in vLLM is not yet optimized and does
-    not usually yield inter-token latency reductions for all prompt datasets or sampling parameters.
-    The work to optimize it is ongoing and can be followed here: <https://github.com/vllm-project/vllm/issues/4630>
-
 !!! warning
     Currently, speculative decoding in vLLM is not compatible with pipeline parallelism.