chore: code linting

Signed-off-by: Vincent Biret <vibiret@microsoft.com>

Author: baywet

test/Microsoft.OpenApi.Readers.Tests/V3Tests/OpenApiDocumentTests.cs

@@ -32,7 +32,7 @@ public OpenApiDocumentTests()
             OpenApiReaderRegistry.RegisterReader(OpenApiConstants.Yaml, new OpenApiYamlReader());
         }
 
-        public T Clone<T>(T element) where T : IOpenApiSerializable
+        private static T Clone<T>(T element) where T : IOpenApiSerializable
         {
             using var stream = new MemoryStream();
             var streamWriter = new FormattingStreamWriter(stream, CultureInfo.InvariantCulture);
@@ -49,7 +49,7 @@ public T Clone<T>(T element) where T : IOpenApiSerializable
             return OpenApiModelFactory.Parse<T>(result, OpenApiSpecVersion.OpenApi3_0, out var _);
         }
 
-        public OpenApiSecurityScheme CloneSecurityScheme(OpenApiSecurityScheme element)
+        private static OpenApiSecurityScheme CloneSecurityScheme(OpenApiSecurityScheme element)
         {
             using var stream = new MemoryStream();
             var streamWriter = new FormattingStreamWriter(stream, CultureInfo.InvariantCulture);