refactor(bigquery): remove redundant Schema cast in queryRpc

Author: jinseopkim0

java-bigquery/google-cloud-bigquery/src/main/java/com/google/cloud/bigquery/BigQueryImpl.java

@@ -2290,9 +2290,7 @@ public com.google.api.services.bigquery.model.QueryResponse call()
       if (isArrow) {
         arrowSchemaBytes = results.getArrowSchema().decodeSerializedSchema();
         try {
-          arrowSchemaPojo =
-              (org.apache.arrow.vector.types.pojo.Schema)
-                  ArrowDeserializer.deserializeSchema(arrowSchemaBytes);
+          arrowSchemaPojo = ArrowDeserializer.deserializeSchema(arrowSchemaBytes);
         } catch (IOException e) {
           throw new BigQueryException(0, "Failed to deserialize Arrow schema from response", e);
         }