boto3.Session() called on import

[Thijss]

Describe the bug

import awswrangler as wr

Also triggers an import of index_json (from awswrangler/opensearch/_write.py)

One of the parameters for index_json initializes a boto3.Session() on import.

@_utils.check_optional_dependency(opensearchpy, "opensearchpy")
def index_json(
    ...
    boto3_session: boto3.Session | None = boto3.Session(),
    ...
    **kwargs: Any,

When running e.g., unit tests, this is quite annoying.

How to Reproduce

import awswrangler as wr

Expected behavior

import awswrangler as wr should not initiate a boto3 session

Your project

No response

Screenshots

No response

OS

MacOS

Python version

3.12.9

AWS SDK for pandas version

3.12.1

Additional context

No response