[FIX] hr_holidays: fix calendar height

Before this commit, calendar view's height was 89.5% of its container.
It was because of hr_holidays module which reduces the calendar's
height to add some elements on top of it.

This commit adds a class `o_timeoff_calendar` on calendar view's
controller to scope css rules only in the hr_holidays module and
set the height to a fixed value.

Task id: 2193921

closes odoo/odoo#54268

Related: odoo/enterprise#12183
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>

addons/hr_holidays/static/src/js/time_off_calendar.js

@@ -36,6 +36,14 @@ odoo.define('hr_holidays.dashboard.view_custo', function(require) {
             'click .btn-allocation': '_onNewAllocation',
         }),
 
+        /**
+         * @override
+         */
+        start: function () {
+            this.$el.addClass('o_timeoff_calendar');
+            return this._super(...arguments);
+        },
+
         //--------------------------------------------------------------------------
         // Public
         //--------------------------------------------------------------------------

addons/hr_holidays/static/src/scss/time_off.scss

@@ -1,10 +1,10 @@
-.o_content {
+.o_timeoff_calendar .o_content {
     .o_timeoff_container {
-        height: 10%;
+        height: 6rem;
     }
 
     .o_calendar_container {
-      height: 89.5%;
+      height: calc(100% - 6rem);
     }
 
     @include media-breakpoint-down(sm) {