When working with s3fs (For AWS S3), it still raises "Polars found a filename" warning

Checks

[X] I have checked that this issue has not already been reported.
[X] I have confirmed this bug exists on the latest version of Polars.

Reproducible example

import polars as pl
import s3fs

df = pl.DataFrame({
    "foo": ["a", "b", "c", "d", "d"],
    "bar": [1, 2, 3, 4, 5],
})

fs = s3fs.S3FileSystem()
destination = "s3://bucket/my_file.parquet"

# write parquet
with fs.open(destination, mode='wb') as f:
    df.write_parquet(f)

Log output

/Users/sanhehu/Documents/GitHub/polars_aws-project/polars_aws/s3/_write_parquet.py:56: UserWarning: Polars found a filename. Ensure you pass a path to the file instead of a python file object when possible for best performance.
    df.write_parquet(f, **kwargs)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html

Issue description

I am following the code in https://docs.pola.rs/user-guide/io/cloud-storage/#writing-to-cloud-storage, how ever, it still raises the "UserWarning: Polars found a filename. Ensure you pass a path to the file instead of a python file object when possible for best performance." warning. I guess it's because the example doesn't match the polars recommended best practice.

Expected behavior

Should not have warning

Installed versions

``` --------Version info--------- Polars: 1.4.0 Index type: UInt32 Platform: macOS-14.3-arm64-arm-64bit Python: 3.10.10 (main, Feb 20 2024, 22:22:03) [Clang 15.0.0 (clang-1500.1.0.2.5)] ----Optional dependencies---- adbc_driver_manager: cloudpickle: connectorx: deltalake: fastexcel: fsspec: 2024.6.1 gevent: great_tables: hvplot: matplotlib: nest_asyncio: numpy: openpyxl: pandas: pyarrow: pydantic: pyiceberg: sqlalchemy: torch: xlsx2csv: xlsxwriter: ```

pola-rs / polars