Suppress 'HTTP/1.1 200 OK' logs from openai library (openai#1468)

Since [the `openai-python` library
update](openai#1444), eval runs are
getting flooded with excessive "HTTP/1.1. 200 OK" logs from the openai
library:
```
junshern@JunSherns-MacBook-Pro ⚒ oaieval gpt-3.5-turbo 2d_movement
[2024-02-15 12:22:08,549] [registry.py:262] Loading registry from /Users/junshern/projects/oss_evals/evals/evals/registry/evals
[2024-02-15 12:22:08,898] [registry.py:262] Loading registry from /Users/junshern/.evals/evals
[2024-02-15 12:22:08,900] [oaieval.py:211] Run started: 240215042208OCODJ2NY
[2024-02-15 12:22:08,949] [data.py:94] Fetching /Users/junshern/projects/oss_evals/evals/evals/registry/data/2d_movement/samples.jsonl
[2024-02-15 12:22:08,949] [eval.py:36] Evaluating 100 samples
[2024-02-15 12:22:08,955] [eval.py:144] Running in threaded mode with 10 threads!
  0%|                                                                                                                                                                                                                                                 | 0/100 [00:00<?, ?it/s][2024-02-15 12:22:10,338] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
  1%|██▎                                                                                                                                                                                                                                      | 1/100 [00:01<02:17,  1.39s/it][2024-02-15 12:22:10,355] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:10,384] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:10,392] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:10,393] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:10,395] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:10,400] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:10,400] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:10,401] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:10,432] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:10,890] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
 11%|█████████████████████████▌                                                                                                                                                                                                              | 11/100 [00:01<00:12,  7.05it/s][2024-02-15 12:22:10,907] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:11,319] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
 13%|██████████████████████████████▏                                                                                                                                                                                                         | 13/100 [00:02<00:13,  6.36it/s][2024-02-15 12:22:11,421] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
 14%|████████████████████████████████▍                                                                                                                                                                                                       | 14/100 [00:02<00:12,  6.65it/s][2024-02-15 12:22:11,463] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:11,504] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:11,524] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:11,542] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
 18%|█████████████████████████████████████████▊                                                                                                                                                                                              | 18/100 [00:02<00:08, 10.17it/s][2024-02-15 12:22:11,564] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:11,564] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:11,565] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:11,570] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
[2024-02-15 12:22:11,829] [_client.py:1027] HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK"
...
```

- This PR adds a `logging.getLogger("httpx").setLevel(logging.WARNING)`
to suppress logs from `httpx` (which is the module within `openai`
generating these logs) below the WARNING level, which quiets these logs.
- I chose to make the change within `evals/utils/api_utils.py` since
that's closest to where the logs are being generated.

After the change:
```
junshern@JunSherns-MacBook-Pro ⚒ oaieval gpt-3.5-turbo 2d_movement
[2024-02-15 12:22:20,408] [registry.py:262] Loading registry from /Users/junshern/projects/oss_evals/evals/evals/registry/evals
[2024-02-15 12:22:20,762] [registry.py:262] Loading registry from /Users/junshern/.evals/evals
[2024-02-15 12:22:20,763] [oaieval.py:211] Run started: 240215042220QS3AJAVA
[2024-02-15 12:22:20,812] [data.py:94] Fetching /Users/junshern/projects/oss_evals/evals/evals/registry/data/2d_movement/samples.jsonl
[2024-02-15 12:22:20,812] [eval.py:36] Evaluating 100 samples
[2024-02-15 12:22:20,819] [eval.py:144] Running in threaded mode with 10 threads!
100%|███████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 100/100 [00:08<00:00, 11.96it/s]
[2024-02-15 12:22:29,217] [record.py:371] Final report: {'accuracy': 0.09, 'boostrap_std': 0.029618636025313522}. Logged to /tmp/evallogs/240215042220QS3AJAVA_gpt-3.5-turbo_2d_movement.jsonl
[2024-02-15 12:22:29,217] [oaieval.py:228] Final report:
[2024-02-15 12:22:29,217] [oaieval.py:230] accuracy: 0.09
[2024-02-15 12:22:29,217] [oaieval.py:230] boostrap_std: 0.029618636025313522
[2024-02-15 12:22:29,233] [record.py:360] Logged 200 rows of events to /tmp/evallogs/240215042220QS3AJAVA_gpt-3.5-turbo_2d_movement.jsonl: insert_time=15.670ms
```

evals/utils/api_utils.py

@@ -10,6 +10,7 @@
 from openai import OpenAI
 
 EVALS_THREAD_TIMEOUT = float(os.environ.get("EVALS_THREAD_TIMEOUT", "40"))
+logging.getLogger("httpx").setLevel(logging.WARNING) # suppress "OK" logs from openai API calls
 
 
 @backoff.on_exception(