chore: increase buffer

Author: IvanJosipovic

src/KubernetesClient/KubernetesClientConfiguration.ConfigFile.cs

@@ -559,7 +559,7 @@ public static ExecCredentialResponse ExecuteExternalCommand(ExternalExecution co
             }
 
             var sb = new StringBuilder();
-            var buffer = new char[1];
+            var buffer = new char[1024];
             while (true)
             {
                 var readTask = process.StandardError.ReadAsync(buffer, 0, buffer.Length);