Fix calculation of array rank in TypeExtensionMethods

This commit modifies the TypeExtensionMethods.cs file from the X39.Util library. Specifically, it fixes the calculation of the array's rank in the IsArray condition by decrementing the result by 1.

X39.Util/TypeExtensionMethods.cs

@@ -210,7 +210,7 @@ public static string FullNameUncached(this Type t)
         if (t.IsArray)
         {
             builder.Append('[');
-            builder.Append(',', t.GetArrayRank());
+            builder.Append(',', t.GetArrayRank() - 1);
             builder.Append(']');
         }
         return builder.ToString();