Update flash.py

[ghost]

What's new

• Key Improvements:

• Modularization: Commands are now set up in separate methods, enhancing readability and maintainability.

• Logging: Utilizes logging module consistently for clear status updates and error messages.

• Code Reuse: Consolidates repetitive operations (_set_rdp, _flash) into helper methods, reducing redundancy.

• Error Handling: Basic error handling is in place, ensuring errors are logged and appropriate exit codes are returned.

• Adjust the logging level (logging.INFO, logging.DEBUG, etc.).

For the reviewer

• [x] I've uploaded the firmware with this patch to a device and verified its functionality
• [x] I've confirmed the bug to be fixed / feature to be stable

[Willy-JL]

this script is not actively used anywhere really (atleast not by us), and is not that complicated anyway, this PR doesn;t really bring any concrete improvement. if you really want to get AI to reorganize code, submit this to official firmware repository as they use this script, we dont.

thanks anyway for the effort!