Support pydantic v2 with v1 shims

[allenporter]

No description provided.

[codecov]

Codecov Report

Merging #207 (7fbc4d2) into main (f250929) will decrease coverage by 0.02%.
The diff coverage is 96.87%.

@@            Coverage Diff             @@
##             main     #207      +/-   ##
==========================================
- Coverage   96.77%   96.76%   -0.02%     
==========================================
  Files          44       44              
  Lines        2608     2655      +47     
==========================================
+ Hits         2524     2569      +45     
- Misses         84       86       +2     

Impacted Files	Coverage Δ
ical/component.py	95.42% <83.33%> (-0.48%)	⬇️
ical/types/parsing.py	89.65% <83.33%> (-2.35%)	⬇️
ical/alarm.py	98.21% <100.00%> (+0.10%)	⬆️
ical/calendar.py	98.46% <100.00%> (+0.07%)	⬆️
ical/calendar_stream.py	97.56% <100.00%> (+0.19%)	⬆️
ical/event.py	97.53% <100.00%> (+0.03%)	⬆️
ical/freebusy.py	98.66% <100.00%> (+0.05%)	⬆️
ical/journal.py	100.00% <100.00%> (ø)
ical/timezone.py	96.66% <100.00%> (+0.06%)	⬆️
ical/todo.py	98.61% <100.00%> (+0.06%)	⬆️
... and 5 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more