[AMORO-4308][lance] Remove redundant getTables call (#4309)

Change-Id: I8ced8b818e8b77f2757f737df7df4a0a425d07e7
(cherry picked from commit 7c791a5)

Author: ddupg

amoro-format-lance/src/main/java/org/apache/amoro/formats/lance/LanceDirectoryV1Catalog.java

@@ -172,8 +172,6 @@ private List<String> listTablesFromNamespace() {
     ListTablesResponse response = namespace.listTables(request);
     if (response == null) {
       return Collections.emptyList();
-    } else {
-      response.getTables();
     }
 
     return new ArrayList<>(response.getTables());