Improve pjit

[mschwoer]

• add the option to deactivate pjit (only functional change: 730572a)
• refactor for readability

[Copilot]

Pull Request Overview

This PR improves the pjit functionality by adding an option to deactivate numba njit, refactoring for readability, and increasing the progress bar sleep time.

• Added a conditional decorator to optionally apply numba.njit via a new parameter.
• Refactored the pjit wrapper and progress callback mechanism.
• Adjusted sleep timing in the progress callback to slow down updates.