Use timezone-aware datetime.datetime.now()

[4n3w]

Replace deprecated datetime.datetime.utcnow() with timezone-aware datetime.datetime.now()

This change addresses a deprecation warning for python 3.12 by using datetime.datetime.now() with datetime.timezone.utc, ensuring the timestamp remains in UTC and conforms to newer best practices.

[kovyrin]

Tested it in my environment and it works

[senderic]

Works for me too

➜  ~ curl https://raw.githubusercontent.com/4n3w/speedtest-cli/fix_datetime_utcnow_deprecation/speedtest.py | python3 
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 65352  100 65352    0     0   263k      0 --:--:-- --:--:-- --:--:--  263k
Retrieving speedtest.net configuration...
Testing from Spectrum (a.b.c.d)...
Retrieving speedtest.net server list...
Selecting best server based on ping...
Hosted by Airlink Internet Inc (Los Angeles, CA) [167.30 km]: 20.176 ms
Testing download speed................................................................................
Download: 196.26 Mbit/s
Testing upload speed......................................................................................................
Upload: 10.62 Mbit/s

[4n3w]

I guess someone with write access would have to merge this, summoning @sivel

[SantiiRepair]

you should update that too

[ckujau]

duplicate of #801 (and would be included in #799 also)?