[BUG] Update the deprecated `utcfromtimestamp` function and reevaluate its usage

[AleksaMCode]

Is there an existing issue for this?

• I have searched the existing issues

Description

The deprecated utcfromtimestamp function should be replaced. Also, the way it's used should be reevaluated. Apparently, usage of datetime.utcfromtimestamp() isn't the best way to work with UTC datetimes.

PNLS version

0.2.0

Python version

3.11.4

Operating system

Linux 5.15.44-Re4son-v8l+

Additional environment/system information

No response

Actual Behavior

No response

Expected Behavior

No response

Steps To Reproduce

No response

Anything else?

These might be useful:

• https://discuss.python.org/t/deprecating-utcnow-and-utcfromtimestamp/26221
• https://blog.ganssle.io/articles/2019/11/utcnow.html