fix: Adds Date property for AriUpdateData

Adds the `Date` property to the `AriUpdateData` model,
allowing a single date to be specified alongside the
existing `FromDate`. This provides more flexibility
when updating Availability, Restrictions, and Inventory (ARI)
data.

Author: Antaris

libs/GuestLineSDK/Ari/AriUpdate.cs

@@ -106,6 +106,12 @@ public class AriUpdateData : Model<AriUpdateData>
 	[JsonPropertyName("ctd"), JsonConverter(typeof(BooleanCharacterJsonConverter))]
 	public bool ClosedToDeparture { get; set; }
 
+	/// <summary>
+	/// Date in YYYY-MM-DD format.
+	/// </summary>
+	[JsonPropertyName("date"), JsonConverter(typeof(DateOnlyJsonConverter))]
+	public DateTime? Date { get; set; }
+
 	/// <summary>
 	/// Date in YYYY-MM-DD format.
 	/// </summary>