[FIX] microsoft_calendar: ensure syncronization with cancelled event

This commit addresses a synchronization issue with Microsoft Calendar,
which arose after the implementation of commit d9c4043.
The mentioned commit added tracking to the pre-commit process,
inadvertently causing problems during calendar synchronization.

The issue surfaced when the `_message_track_post_template` function was
called in the pre-commit phase. If the appointment function was
installed, the `_track_template` was overridden in this module, leading
to an attempt to access the removed event, which raised an error and
prevented calendar synchronization.

With this modification, the `_track_template` will not be called for
the created event that was cancelled in the same transaction.

opw-3635261

closes odoo/odoo#148439

X-original-commit: f46276590f62bc578aab954a88e495519b46a07a
Signed-off-by: Arnaud Joset (arj) <arj@odoo.com>

addons/microsoft_calendar/models/calendar.py

@@ -638,6 +638,9 @@ class Meeting(models.Model):
         """
         user = self.env.user
         records = self.filtered(lambda e: not e.user_id or e.user_id == user or user.partner_id in e.partner_ids)
+        for event in records:
+            # remove the tracking data to avoid calling _track_template in the pre-commit phase
+            self.env.cr.precommit.data.pop(f'mail.tracking.create.{event._name}.{event.id}', None)
         super(Meeting, records)._cancel_microsoft()
         attendees = (self - records).attendee_ids.filtered(lambda a: a.partner_id == user.partner_id)
         attendees.do_decline()