fix: hidi fails to parse yaml files when fixing references

Author: baywet

src/Microsoft.OpenApi.Hidi/OpenApiService.cs

@@ -438,7 +438,10 @@ private static async Task<ReadResult> ParseOpenApiAsync(string openApiFile, bool
             var sb = new StringBuilder();
             document.SerializeAsV3(new OpenApiYamlWriter(new StringWriter(sb)));
 
-            var doc = OpenApiDocument.Parse(sb.ToString(), format).Document;
+            var settings = new OpenApiReaderSettings();
+            settings.AddYamlReader();
+
+            var doc = OpenApiDocument.Parse(sb.ToString(), format, settings).Document;
 
             return doc;
         }