[CI][Python] test-conda-python is failing due to new DeprecationWarning raised on aiohttp

[raulcd]

Describe the bug, including details regarding any error messages, version, and platform.

On the test-conda-python nightly builds we have enabled Warnings as errors: #37018
This is currently causing some nightly failures due to a new DeprecationWarning being raised by aiohttp due to s3fs:

https://github.com/ursacomputing/crossbow/actions/runs/6489587884/job/17624099591#step:6:8770

self = <aiohttp.client.ClientSession object at 0x7f184812d770>
name = '_resolve_charset'
val = <function _default_fallback_charset_resolver at 0x7f184b380260>

    def __setattr__(self, name: str, val: Any) -> None:
        if name not in self.ATTRS:
>           warnings.warn(
                "Setting custom ClientSession.{} attribute "
                "is discouraged".format(name),
                DeprecationWarning,
                stacklevel=2,
            )
E           DeprecationWarning: Setting custom ClientSession._resolve_charset attribute is discouraged

opt/conda/envs/arrow/lib/python3.10/site-packages/aiohttp/client.py:354: DeprecationWarning

test-conda-python-3.10
test-conda-python-3.11
test-conda-python-3.12
test-conda-python-3.8
test-conda-python-3.9

Component(s)

Continuous Integration, Python