[REF] calendar: remove cron activation code

There is code that automatically enable or disable the cron whether it
exists alarms. As alarms are automatically added, the cron is actually
always enabled.

addons/calendar/data/calendar_cron.xml

@@ -7,7 +7,7 @@
             <field name="model_id" ref="model_calendar_alarm_manager"/>
             <field name="state">code</field>
             <field name="code">model.get_next_mail()</field>
-            <field eval="False" name="active" />
+            <field eval="True" name="active" />
             <field name="user_id" ref="base.user_root" />
             <field name="interval_number">30</field>
             <field name="interval_type">minutes</field>
@@ -15,4 +15,4 @@
             <field eval="False" name="doall" />
         </record>
     </data>
-</odoo>
+</odoo>

addons/calendar/models/calendar_alarm.py

@@ -49,26 +49,3 @@ class Alarm(models.Model):
             key: value for key, value in self._fields['alarm_type']._description_selection(self.env)
         }[self.alarm_type]
         self.name = "%s - %s %s" % (display_alarm_type, self.duration, display_interval)
-
-    def _update_cron(self):
-        try:
-            cron = self.env['ir.model.data'].sudo().get_object('calendar', 'ir_cron_scheduler_alarm')
-        except ValueError:
-            return False
-        return cron.toggle(model=self._name, domain=[('alarm_type', '=', 'email')])
-
-    @api.model
-    def create(self, values):
-        result = super(Alarm, self).create(values)
-        self._update_cron()
-        return result
-
-    def write(self, values):
-        result = super(Alarm, self).write(values)
-        self._update_cron()
-        return result
-
-    def unlink(self):
-        result = super(Alarm, self).unlink()
-        self._update_cron()
-        return result

addons/calendar/models/calendar_alarm_manager.py

@@ -74,6 +74,7 @@ class AlarmManager(models.AbstractModel):
             first_alarm_max_value = "(now() at time zone 'utc' + interval '%s' second )"
             tuple_params += (seconds,)
 
+        self.flush()
         self._cr.execute("""
             WITH calcul_delta AS (%s)
             SELECT *