Create tests for automation scripts in the tests/ folder

[RickyDicaprio]

To ensure all automation scripts work correctly, we need unit tests for each script in the scripts/ folder.

Tasks:
1. Add tests/test_backup_folder.py for backup_folder.py
2. Add tests/test_cleanup_temp.py for cleanup_temp.py
3. Add tests/test_sample_hello.py for sample_hello.py
4. Add tests/test_utils.py for any helper functions
5. Ensure tests can be run using run_tests.sh
6. Update docs/how_to_run_scripts.md with instructions to run tests

Goal:
Provide a reliable test suite so contributors can verify their scripts before submitting PRs.