Dataset UI shows 0:00/0:00 for audio after push_to_hub

I’m seeing an issue where audio previews in the dataset viewer show `0:00/0:00` after uploading with push_to_hub.

## What I did

I tried to avoid `torchcodec`  because I want to keep the packages small  using the following code:

```python
import io
import os
import shutil
import tempfile
from pathlib import Path

import pyarrow as pa
import soundfile as sf
from datasets import Audio, Dataset, DatasetInfo, Features
from datasets.table import InMemoryTable
from dotenv import load_dotenv
from loguru import logger

load_dotenv()

AUDIO_EXTENSIONS = {".flac", ".wav", ".mp3", ".ogg"}

HF_TOKEN = os.environ.get("HF_TOKEN", "")
TARGET_DATASET = "madoss/test-infra"
SAMPLES_DIR = Path(__file__).parent / "samples"

_AUDIO_PA_TYPE = pa.struct(
    [
        pa.field("bytes", pa.binary()),
        pa.field("path", pa.string()),
    ]
)


def _to_flac_bytes(path: Path) -> bytes:
    data, sr = sf.read(str(path), dtype="float32", always_2d=False)
    if data.ndim > 1:
        data = data.mean(axis=1)
    buf = io.BytesIO()
    sf.write(buf, data, sr, format="FLAC")
    return buf.getvalue()


def build_dataset(samples_dir: Path) -> Dataset:
    audio_files = sorted(p for p in samples_dir.iterdir() if p.suffix in AUDIO_EXTENSIONS)
    if not audio_files:
        raise SystemExit(f"No audio files found in {samples_dir}")
    logger.info(f"Found {len(audio_files)} audio files")

    rows = []
    with tempfile.TemporaryDirectory() as tmpdir:
        for src in audio_files:
            dst = Path(tmpdir) / src.name
            shutil.copy2(src, dst)
            audio_bytes = _to_flac_bytes(dst)
            rows.append({"bytes": audio_bytes, "path": src.name})
    table = pa.table({"audio": pa.array(rows, type=_AUDIO_PA_TYPE)})
    return Dataset(
        InMemoryTable(table),
        info=DatasetInfo(features=Features({"audio": Audio(decode=False)})),
    )


def main():
    logger.info("Loading VAD model...")

    logger.info("Building dataset...")
    ds = build_dataset(SAMPLES_DIR)
    logger.info(f"Dataset: {ds}")
    logger.info(f"Features: {ds.features}")

    logger.info(f"Pushing to {TARGET_DATASET}...")
    ds.push_to_hub(TARGET_DATASET, token=HF_TOKEN or None)
    logger.info(f"Done → https://huggingface.co/datasets/{TARGET_DATASET}")


if __name__ == "__main__":
    main()
```

## Expected behavior

In the dataset UI, each audio sample should display its real duration and be playable with a normal timeline (for example, 0:00 / 0:05).

## Actual behavior
The UI shows 0:00/0:00 for audio samples.

<img width="1104" height="574" alt="Image" src="https://github.com/user-attachments/assets/5a7ab709-b67d-4e73-9165-10476c2d227f" />

## Environment

- `datasets==4.8.4, pyarrow==24.0.0`
- `Python 3.12.10`
- `Ubuntu 24.04.4`

Comments:
Hello,
I am trying to find my first issue to resolve. I can't reproduce your problem. When I go in the hub UI to your dataset. I can see the length of each audio. It takes some time to load 

## Dataset Card
<img width="584" height="644" alt="Image" src="https://github.com/user-attachments/assets/8b0e38fb-a922-49be-9698-f7b8e0c68ad5" />

## Data Studio UI
<img width="615" height="580" alt="Image" src="https://github.com/user-attachments/assets/10de4323-9896-4102-9204-5df824fc2acb" />