[#217] resolve "blocking call" warning log.

[jekalmin]

Issue

• Blocking call to open inside event loop warnings on 2024.6 dev #217

2024-10-27 13:45:53.213 WARNING (MainThread) [homeassistant.util.loop] Detected blocking call to load_verify_locations with args (<ssl.SSLContext object at 0x7bebd793ddd0>,) inside the event loop by custom integration 'extended_openai_conversation' at custom_components/extended_openai_conversation/helpers.py, line 146: client = AsyncOpenAI( (offender: /home/vscode/.local/ha-venv/lib/python3.12/site-packages/httpx/_config.py, line 149: context.load_verify_locations(cafile=cafile)), please create a bug report at https://github.com/jekalmin/extended_openai_conversation/issues
For developers, please see https://developers.home-assistant.io/docs/asyncio_blocking_operations/#load_verify_locations

Objective

• Fix blocking call to verify cafile.