fix avoid creating a client for each request in hidi

Signed-off-by: Vincent Biret <[email protected]>

Author: baywet

src/Microsoft.OpenApi.Hidi/OpenApiService.cs

@@ -492,6 +492,11 @@ private static Dictionary<string, List<string>> EnumerateJsonDocument(JsonElemen
             return paths;
         }
 
+        private static readonly Lazy<HttpClient> httpClient = new(() => new HttpClient()
+        {
+            DefaultRequestVersion = HttpVersion.Version20
+        });
+
         /// <summary>
         /// Reads stream from file system or makes HTTP request depending on the input string
         /// </summary>
@@ -507,11 +512,7 @@ private static async Task<Stream> GetStreamAsync(string input, ILogger logger, C
                 {
                     try
                     {
-                        using var httpClient = new HttpClient
-                        {
-                            DefaultRequestVersion = HttpVersion.Version20
-                        };
-                        stream = await httpClient.GetStreamAsync(new Uri(input), cancellationToken).ConfigureAwait(false);
+                        stream = await httpClient.Value.GetStreamAsync(new Uri(input), cancellationToken).ConfigureAwait(false);
                     }
                     catch (HttpRequestException ex)
                     {