gui/event-popover: Show at the top

Seems slightly less worse than showing at the sides of the event.

Related: https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/1006

src/gui/gcal-event-popover.c

@@ -709,11 +709,6 @@ static void
 gcal_event_popover_init (GcalEventPopover *self)
 {
   gtk_widget_init_template (GTK_WIDGET (self));
-
-  if (gtk_widget_get_direction (GTK_WIDGET (self)) == GTK_TEXT_DIR_RTL)
-    gtk_popover_set_position (GTK_POPOVER (self), GTK_POS_LEFT);
-  else
-    gtk_popover_set_position (GTK_POPOVER (self), GTK_POS_RIGHT);
 }
 
 GtkWidget*

src/gui/gcal-event-popover.ui

@@ -2,6 +2,7 @@
 <interface>
   <template class="GcalEventPopover" parent="GtkPopover">
     <property name="default-widget">edit_button</property>
+    <property name="position">top</property>
 
     <style>
       <class name="event-popover" />