Sync OS names

Author: mthalman

tests/Microsoft.DotNet.Docker.Tests/OS.cs

@@ -30,6 +30,7 @@ public class OS
         public const string Focal = "focal";
         public const string Jammy = "jammy";
         public const string JammyChiseled = "jammy-chiseled";
+        public const string UbuntuChiseled = "ubuntu-chiseled";
 
         // Windows
         public const string NanoServer = "nanoserver";