Add a timeout to the Python file execution step - prevents infinite wait

[A-D-Fuchs]

Add a timeout to the subprocess.run() function call when using the Execute Python File protocol step.
This timeout should probably default to 30s or so, but should be changeable in the GUI of the step.
Without a timeout the function call will wait for ever, even if the Python file doesn't exist or other errors occur.

Change should be done here
https://github.com/FAU-LAP/NOMAD-CAMELS/blob/a4743afee48fd1630aab8d3a6ce46ee609c7a12a/nomad_camels/loop_steps/execute_python_file.py