Fixes an issue where cancellation emails were sending ICS files with
METHOD:REQUEST instead of METHOD:CANCEL. As per RFC 5546, calendar
clients only process cancellations correctly when METHOD:CANCEL is used,
otherwise cancelled events remain in attendee calendars with active
reminders.
- Use METHOD:CANCEL for cancelled booking ICS files
- Keep METHOD:REQUEST for non-cancelled booking invitations
- Preserve STATUS:CANCELLED and sequence handling
- Add tests to verify the generated ICS method for cancellations
Gaurav Kumar
188aaa1857