BUG: defaulting to UTC tz rather than to None

[bsipocz]

This made sense while doing the fixes for scientific-python/scientific-python.org#782, but also I separated it out as it may or may not be necessary.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.69%. Comparing base (b0176a1) to head (7454841).
⚠️ Report is 19 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #116      +/-   ##
==========================================
- Coverage   95.41%   94.69%   -0.73%     
==========================================
  Files           1        1              
  Lines         109      113       +4     
==========================================
+ Hits          104      107       +3     
- Misses          5        6       +1     

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[stefanv]

I think either change the default, or change the handling below, but not both.

[bsipocz]

I feel it makes most sense to change the default here, and then let the event timezone overwrite. Or it maybe cleaner to drop the tz kwarg altogether and rely only on the yaml and have a conditional?

    if "timezone" in d:
        tz = gettz(d.pop("timezone"))
    else:
        tz = dateutil.tz.UTC