Added CU18 for 2019 as not merged yet

Added 2019 CU18

Author: Ant-Green

SqlServerVersions.sql

@@ -42,6 +42,7 @@ INSERT INTO dbo.SqlServerVersions
     (MajorVersionNumber, MinorVersionNumber, Branch, [Url], ReleaseDate, MainstreamSupportEndDate, ExtendedSupportEndDate, MajorVersionName, MinorVersionName)
 VALUES
     (16, 600, 'CTP2', 'https://support.microsoft.com/en-us/help/5011644', '2022-05-24', '2022-05-24', '2022-05-24', 'SQL Server 2022', 'CTP 2.0'),
+    (15, 4261, 'CU18', 'https://support.microsoft.com/en-us/help/5017593', '2022-09-28', '2025-01-07', '2030-01-08', 'SQL Server 2019', 'Cumulative Update 18'),
     (15, 4249, 'CU17', 'https://support.microsoft.com/en-us/help/5016394', '2022-08-11', '2025-01-07', '2030-01-08', 'SQL Server 2019', 'Cumulative Update 17'),
     (15, 4236, 'CU16 GDR', 'https://support.microsoft.com/en-us/help/5014353', '2022-06-14', '2025-01-07', '2030-01-08', 'SQL Server 2019', 'Cumulative Update 16 GDR'),
     (15, 4223, 'CU16', 'https://support.microsoft.com/en-us/help/5011644', '2022-04-18', '2025-01-07', '2030-01-08', 'SQL Server 2019', 'Cumulative Update 16'),