style: 优化滚动条显示，只有在内容超过显示高度时才会出现 (#1978)

src/components/Table/src/BasicTable.vue

@@ -401,6 +401,10 @@
       width: 100%;
       overflow-x: hidden;
 
+      .ant-table-body {
+        overflow: auto !important;
+      }
+
       &-title {
         display: flex;
         padding: 8px 6px;