[XPU][CI] fix test_qwen2_5_omni_expansion.py::test_mix_to_audio (#3761)

Signed-off-by: Chendi Xue <chendi.xue@intel.com>

docker/Dockerfile.xpu

@@ -133,6 +133,11 @@ ENTRYPOINT []
 
 FROM ${VLLM_BASE} AS vllm-omni
 
+RUN apt-get update && \
+    apt-get install -y espeak-ng ffmpeg git jq && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
+
 WORKDIR /workspace/vllm-omni
 COPY . .