[FIX] google_calendar: Change logger type from error to exception

In sentry we receive like 2k syncing issue from google_calendar.

This commit converts `_logger.error` to `_logger.warning` because we don't
need an erro for that

sentry-4121123364
https://online.sentry.io/issues/4121123364

closes odoo/odoo#119742

X-original-commit: e797712561113f098edc1346995cecd7e96ad362
Signed-off-by: Arnaud Joset <arj@odoo.com>
Signed-off-by: Achraf <abz@odoo.com>

addons/google_calendar/models/google_sync.py

@@ -209,7 +209,7 @@ class GoogleSync(models.AbstractModel):
             error_log += "The event (%(id)s - %(name)s at %(start)s) could not be synced. It will not be synced while " \
                          "it is not updated. Reason: %(reason)s" % {'id': event_ids, 'start': start, 'name': name,
                                                                     'reason': reason}
-            _logger.error(error_log)
+            _logger.warning(error_log)
 
             body = _("The following event could not be synced with Google Calendar.") + Markup("<br/>") + \
                    _("It will not be synced as long at it is not updated.") + Markup("<br/>") + \