Remove unnecessary usings

Author: MaggieKimani1

src/Microsoft.OpenApi/Any/OpenApiAnyCloneHelper.cs

@@ -2,9 +2,6 @@
 // Licensed under the MIT license.
 
 using System.Reflection;
-using Microsoft.OpenApi.Helpers;
-using System.Text.Json.Serialization;
-using System.Text.Json;
 
 namespace Microsoft.OpenApi.Any
 {

src/Microsoft.OpenApi/Models/OpenApiCallback.cs

@@ -2,9 +2,7 @@
 // Licensed under the MIT license. 
 
 using System.Collections.Generic;
-using Microsoft.OpenApi.Any;
 using Microsoft.OpenApi.Expressions;
-using Microsoft.OpenApi.Helpers;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Writers;
 

src/Microsoft.OpenApi/Models/OpenApiComponents.cs

@@ -3,7 +3,6 @@
 
 using System.Collections.Generic;
 using System.Linq;
-using Microsoft.OpenApi.Helpers;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Writers;
 

src/Microsoft.OpenApi/Models/OpenApiDocument.cs

@@ -8,7 +8,6 @@
 using System.Security.Cryptography;
 using System.Text;
 using Microsoft.OpenApi.Exceptions;
-using Microsoft.OpenApi.Helpers;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Services;
 using Microsoft.OpenApi.Writers;

src/Microsoft.OpenApi/Models/OpenApiEncoding.cs

@@ -2,9 +2,7 @@
 // Licensed under the MIT license. 
 
 using System.Collections.Generic;
-using Microsoft.OpenApi.Any;
 using Microsoft.OpenApi.Extensions;
-using Microsoft.OpenApi.Helpers;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Writers;
 

src/Microsoft.OpenApi/Models/OpenApiExample.cs

@@ -3,7 +3,6 @@
 
 using System.Collections.Generic;
 using Microsoft.OpenApi.Any;
-using Microsoft.OpenApi.Helpers;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Writers;
 

src/Microsoft.OpenApi/Models/OpenApiHeader.cs

@@ -4,7 +4,6 @@
 using System.Collections.Generic;
 using Microsoft.OpenApi.Any;
 using Microsoft.OpenApi.Extensions;
-using Microsoft.OpenApi.Helpers;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Writers;
 

src/Microsoft.OpenApi/Models/OpenApiMediaType.cs

@@ -3,7 +3,6 @@
 
 using System.Collections.Generic;
 using Microsoft.OpenApi.Any;
-using Microsoft.OpenApi.Helpers;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Writers;
 

src/Microsoft.OpenApi/Models/OpenApiParameter.cs

@@ -3,10 +3,8 @@
 
 using System;
 using System.Collections.Generic;
-using System.Runtime;
 using Microsoft.OpenApi.Any;
 using Microsoft.OpenApi.Extensions;
-using Microsoft.OpenApi.Helpers;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Writers;
 

src/Microsoft.OpenApi/Models/OpenApiPathItem.cs

@@ -1,10 +1,8 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license. 
 
-using System;
 using System.Collections.Generic;
 using Microsoft.OpenApi.Extensions;
-using Microsoft.OpenApi.Helpers;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Writers;