Race condition when using Application Inference Profile with Bedrock plugin

The `get_inference_profile_info` function has a race condition in its caching logic. When multiple concurrent requests arrive, they will all pass the cache check before any thread can populate the cache, causing a thundering herd of duplicate API calls to `GetInferenceProfile` on Bedrock.

This can be replicated by:
- Add a custom model using an application inference profile ID to the Bedrock plugin
- In Studio, create a new chatbot app and set the newly imported model as the default
- Publish the app
- Send 100+ concurrent requests to this endpoint, (e.g., `http://localhost/v1/chat-messages`)

The expected behavior is that `GetInferenceProfile` will only be called once, and the rest of the requests should just use the cached data. However, you will notice from CloudTrail that this will result in 50-100 invocations to `GetInferenceProfile`.

`GetInferenceProfile` is a control plane API with a fairly low TPS (double digits based on my testing) that cannot be increased. The race condition can cause `ThrottlingException` errors during batch operations or with sufficient concurrent users, resulting in 500 errors.