bugs：Update api.py

[PurpleWZG]

If all agents are selected, the program encounters an error while running the run_hedge_fund function. Specifically, when invoking the michael_burry_agent function and executing the get_company_news method to request news data for Apple Inc. (AAPL), an HTTP 429 error is encountered. The HTTP 429 error indicates that the requests have been rate-limited, and the server's response suggests that requests can be resumed after a 30-second wait.
The server enforces request frequency limits. When an excessive number of requests are sent in a short period, the rate-limiting mechanism is triggered, resulting in a 429 error response.
To address this issue, you can add a retry mechanism with delays to the get_company_news function. This involves pausing for a specified period before retrying failed requests, typically using exponential backoff to gradually increase wait times between attempts.