Fixed a bug where the OpenAPI V3 spec was incorrect. The bug was intr…

…oduced in datahub-project#10939.

metadata-service/openapi-servlet/src/main/java/io/datahubproject/openapi/config/SpringWebConfig.java

@@ -16,6 +16,7 @@
 import io.swagger.v3.oas.models.Components;
 import io.swagger.v3.oas.models.OpenAPI;
 import java.util.Collections;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -150,6 +151,11 @@ private <K, V> Map<K, V> concat(Supplier<Map<K, V>> a, Supplier<Map<K, V>> b) {
         : b.get() == null
             ? a.get()
             : Stream.concat(a.get().entrySet().stream(), b.get().entrySet().stream())
-                .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+                .collect(
+                    Collectors.toMap(
+                        Map.Entry::getKey,
+                        Map.Entry::getValue,
+                        (v1, v2) -> v1,
+                        LinkedHashMap::new));
   }
 }