Australia - Fix Friday before AFL Grand Final for 2024 (#721)

* Cleanup code

* Add missing date for 2024 Friday before AFL Grand Final

Author: tinohager

src/Nager.Date/HolidayProviders/AustraliaHolidayProvider.cs

@@ -54,11 +54,6 @@ protected override IEnumerable<HolidaySpecification> GetHolidaySpecifications(in
             var firstMondayInOctober = DateHelper.FindDay(year, Month.October, DayOfWeek.Monday, Occurrence.First);
             var firstTuesdayInNovember = DateHelper.FindDay(year, Month.November, DayOfWeek.Tuesday, Occurrence.First);
 
-            //var newYearsDay = new DateTime(year, 1, 1).Shift(saturday => saturday.AddDays(2), sunday => sunday.AddDays(1));
-            //var christmasDay = new DateTime(year, 12, 25).Shift(saturday => saturday.AddDays(2), sunday => sunday.AddDays(2));
-            //var boxingDay = new DateTime(year, 12, 26).Shift(saturday => saturday.AddDays(2), sunday => sunday.AddDays(2));
-            //var australiaDay = new DateTime(year, 1, 26).Shift(saturday => saturday.AddDays(2), sunday => sunday.AddDays(1));
-
             var weekendObservedRuleSet = new ObservedRuleSet
             {
                 Saturday = date => date.AddDays(2), Sunday = date => date.AddDays(1),
@@ -332,6 +327,7 @@ private HolidaySpecification[] MonarchBirthday(int year)
                 case 2019:
                 case 2021:
                 case 2023:
+                case 2024:
                     {
                         var lastFridayInSeptember = DateHelper.FindLastDay(year, Month.September, DayOfWeek.Friday);