added timezone aware datetime function

[aryanbhosale]

Pull Request

Description

the datetime.utcnow() method is considered deprecated in modern Python versions, and it's recommended to use the more explicit datetime.now(tz=datetime.timezone.utc) instead. The utcnow() method is still functional, but it's considered less clear and less timezone-aware than the alternative. I have thus replaced the deprecated method with the newer one

Fixes #

528

Checklist:

• [x] My code follows OCF's coding style guidelines
• [x] I have performed a self-review of my own code
• [x] I have checked my code and corrected any misspellings