Movement/TaxiPath: Properly clean up list of taxi destinations upon arrival at final node.

Port From (https://github.com/TrinityCore/TrinityCore/commit/390001fa624ef996d2ae5331e201f9e2d640211b)

Source/Game/Entities/Player/PlayerTaxi.cs

@@ -173,6 +173,8 @@ namespace Game.Entities
             if (m_TaxiDestinations.Empty())
                 return "";
 
+            Cypher.Assert(m_TaxiDestinations.Count >= 2);
+
             StringBuilder ss = new();
             ss.Append($"{m_flightMasterFactionId} ");
 

Source/Game/Movement/Generators/FlightPathMovementGenerator.cs

@@ -123,6 +123,7 @@ namespace Game.Movement
             if (!active)
                 return;
 
+            owner.m_taxi.ClearTaxiDestinations();
             owner.Dismount();
             owner.RemoveUnitFlag(UnitFlags.RemoveClientControl | UnitFlags.TaxiFlight);