Patch SGL Benchmark Test for Pytest Dashboard

[stbaione]

Description

The nightly SGLang benchmark tests had first successful run last night: https://github.com/nod-ai/shark-ai/actions/runs/11850084805/job/33024395622

And uploaded to dashboard successfully: https://nod-ai.github.io/shark-ai/llm/sglang/?sort=result

However, since I used a mock to pipe the bench_serving script output to logger.info, we ended up with results appearing in runner log, that did not appear in dashboard:

============ Serving Benchmark Result ============
INFO     __name__:mock.py:1189 Backend:                                 shortfin  
INFO     __name__:mock.py:1189 Traffic request rate:                    4         
INFO     __name__:mock.py:1189 Successful requests:                     10        
INFO     __name__:mock.py:1189 Benchmark duration (s):                  716.95    
INFO     __name__:mock.py:1189 Total input tokens:                      1960      
INFO     __name__:mock.py:1189 Total generated tokens:                  2774      
INFO     __name__:mock.py:1189 Total generated tokens (retokenized):    291       
INFO     __name__:mock.py:1189 Request throughput (req/s):              0.01      
INFO     __name__:mock.py:1189 Input token throughput (tok/s):          2.73      
INFO     __name__:mock.py:1189 Output token throughput (tok/s):         3.87      
INFO     __name__:mock.py:1189 ----------------End-to-End Latency----------------
INFO     __name__:mock.py:1189 Mean E2E Latency (ms):                   549509.25 
INFO     __name__:mock.py:1189 Median E2E Latency (ms):                 578828.23 
INFO     __name__:mock.py:1189 ---------------Time to First Token----------------
INFO     __name__:mock.py:1189 Mean TTFT (ms):                          327289.54 
INFO     __name__:mock.py:1[189](https://github.com/nod-ai/shark-ai/actions/runs/11850084805/job/33024395622#step:8:190) Median TTFT (ms):                        367482.31 
INFO     __name__:mock.py:1189 P99 TTFT (ms):                           367972.81 
INFO     __name__:mock.py:1189 -----Time per Output Token (excl. 1st token)------
INFO     __name__:mock.py:1189 Mean TPOT (ms):                          939.35    
INFO     __name__:mock.py:1189 Median TPOT (ms):                        886.13    
INFO     __name__:mock.py:1189 P99 TPOT (ms):                           2315.83   
INFO     __name__:mock.py:1189 ---------------Inter-token Latency----------------
INFO     __name__:mock.py:1189 Mean ITL (ms):                           732.59    
INFO     __name__:mock.py:1189 Median ITL (ms):                         729.43    
INFO     __name__:mock.py:1189 P99 ITL (ms):                            1477.77   
INFO     __name__:mock.py:1189 ==================================================

It also had a small bug that was obfuscated in runner/terminal logs, but appeared in dashboard, which prevented jsonl files from being generated after benchmark results were collected.

By fixing the bug in bench_serving input args, and logging resulting jsonl file after each run, I was able to verify locally that the output html contains the proper results: