feat: clean up environment call outs

Author: stainless-app[bot]

README.md

@@ -79,15 +79,14 @@ pip install onebusaway[aiohttp]
 Then you can enable it by instantiating the client with `http_client=DefaultAioHttpClient()`:
 
 ```python
-import os
 import asyncio
 from onebusaway import DefaultAioHttpClient
 from onebusaway import AsyncOnebusawaySDK
 
 
 async def main() -> None:
     async with AsyncOnebusawaySDK(
-        api_key=os.environ.get("ONEBUSAWAY_API_KEY"),  # This is the default and can be omitted
+        api_key="My API Key",
         http_client=DefaultAioHttpClient(),
     ) as client:
         current_time = await client.current_time.retrieve()