[Refactor] Remove dependency on librosa (#2273)

Signed-off-by: Nick Cao <ncao@redhat.com>
Co-authored-by: Claude <noreply@anthropic.com>

docs/user_guide/examples/online_serving/bagel.md

@@ -357,13 +357,6 @@ curl http://localhost:8091/v1/chat/completions \
 
 ## FAQ
 
-- If you encounter an error about the backend of librosa, try to install ffmpeg with the command below.
-
-```bash
-sudo apt update
-sudo apt install ffmpeg
-```
-
 - If you don’t know how much VRAM is needed for the model or encounter the OOM error, you can try to decrease the max_model_len.
 
 | Stage               | VRAM                         |

docs/user_guide/examples/online_serving/qwen2_5_omni.md

@@ -218,14 +218,6 @@ The gradio script supports the following arguments:
 - `--port`: Port for Gradio server (default: 7861)
 - `--share`: Share the Gradio demo publicly (creates a public link)
 
-### FAQ
-
-If you encounter error about backend of librosa, try to install ffmpeg with command below.
-```
-sudo apt update
-sudo apt install ffmpeg
-```
-
 ## Example materials
 
 ??? abstract "gradio_demo.py"

docs/user_guide/examples/online_serving/qwen3_omni.md

@@ -64,15 +64,6 @@ python openai_chat_completion_client_for_multimodal_generation.py \
 bash run_curl_multimodal_generation.sh use_image
 ```
 
-
-### FAQ
-
-If you encounter error about backend of librosa, try to install ffmpeg with command below.
-```
-sudo apt update
-sudo apt install ffmpeg
-```
-
 ## Modality control
 You can control output modalities to specify which types of output the model should generate. This is useful when you only need text output and want to skip audio generation stages for better performance.
 

docs/user_guide/examples/online_serving/qwen3_tts.md

@@ -211,14 +211,6 @@ with open("output.wav", "wb") as f:
     f.write(response.content)
 ```
 
-### FAQ
-
-If you encounter error about backend of librosa, try to install ffmpeg with command below.
-```
-sudo apt update
-sudo apt install ffmpeg
-```
-
 ## API Reference
 
 ### Voices Endpoint