rewriting deprecated modal scaledownwindow and adding pydra config

[pythonomar22]

When running the scripts/generate_baseline_time_modal.py, I updated the deprecated "container_idle_timeout" argument in the modal app to scaledown window:

 See https://modal.com/docs/guide/modal-1-0-migration for more details.
  @app.cls(image=image, container_idle_timeout=5)
/Users/omarabul-hassan/Desktop/projects/KernelBench/scripts/generate_baseline_time_modal.py:147: DeprecationError: 2025-02-24: We have renamed several parameters related to autoscaling. Please update your code to use the following new names:

- container_idle_timeout -> scaledown_window

Also, I added a pydra config to the file so that we can specify what GPU to use on Modal thru command line, as well as number of trials, if you only want to generate baseline times for a given level.