Remove empty list initialization

Author: MaggieKimani1

src/Microsoft.OpenApi/Models/OpenApiDocument.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license.
 
 using System;
@@ -48,8 +48,7 @@ public class OpenApiDocument : IOpenApiSerializable, IOpenApiExtensible, IOpenAp
         /// <summary>
         /// A declaration of which security mechanisms can be used across the API.
         /// </summary>
-        public IList<OpenApiSecurityRequirement> SecurityRequirements { get; set; } =
-            new List<OpenApiSecurityRequirement>();
+        public IList<OpenApiSecurityRequirement> SecurityRequirements { get; set; }
 
         /// <summary>
         /// A list of tags used by the specification with additional metadata.

src/Microsoft.OpenApi/Models/OpenApiOperation.cs

@@ -91,7 +91,7 @@ public class OpenApiOperation : IOpenApiSerializable, IOpenApiExtensible, IOpenA
         /// This definition overrides any declared top-level security.
         /// To remove a top-level security declaration, an empty array can be used.
         /// </summary>
-        public IList<OpenApiSecurityRequirement> Security { get; set; } = new List<OpenApiSecurityRequirement>();
+        public IList<OpenApiSecurityRequirement> Security { get; set; }
 
         /// <summary>
         /// An alternative server array to service this operation.