e6600555

By: Tom Sydney Kerckhove <syd@cs-syd.eu>

ical-recurrence: test an ExceptionDateTimes given in another time zone

[section 3.8.5.1](https://datatracker.ietf.org/doc/html/rfc5545#section-3.8.5.1)

@
Property Parameters:  IANA, non-standard, value data type, and time
   zone identifier property parameters can be specified on this
   property.
@

Nothing ties the time zone of an EXDATE to the one DTSTART uses, so a
conforming exception can name an instance in another time zone from the
one the instance itself is written in: 02:00 at +0200 is the same instant
as an instance at 01:00 at +0100.

These pass already.  Comparing exception dates on resolved instants, in
the commit that fixed the same problem for an EXDATE given in UTC, fixed
this case at the same time, so this is coverage rather than a fix and has
no accompanying change.

Both tests are worth keeping regardless of that.  The first covers a case
the UTC one does not, and the second is the one that rules out comparing
the local times while ignoring which time zone each of them is in, which
would satisfy every test written for the UTC case while being wrong here.

Timeline