fix: search issue of post tag selection component (#3540)

#### What type of PR is this?

/kind bug
/area console

#### What this PR does / why we need it:

修复 FormKit 的文章标签搜索组件无法使用搜索功能的问题。

<img width="720" alt="image" src="https://user-images.githubusercontent.com/21301288/226311996-8f31bc6c-784e-4bf0-93da-cdc6db935822.png">

#### Which issue(s) this PR fixes:

Fixed https://github.com/halo-dev/halo/issues/3536

#### Special notes for your reviewer:

测试方式：

1. 在文章设置中，测试标签选择输入框的搜索功能是否正常即可。

#### Does this PR introduce a user-facing change?

```release-note
修复文章设置中的标签选择组件无法正常搜索的问题。
```

console/src/formkit/inputs/tag-select/TagSelect.vue

@@ -52,11 +52,11 @@ const { tags: postTags, handleFetchTags } = usePostTag();
 let fuse: Fuse<Tag> | undefined = undefined;
 
 const searchResults = computed(() => {
-  if (!fuse || !text.value) {
+  if (!text.value) {
     return postTags.value;
   }
 
-  return fuse?.search(text.value).map((item) => item.item);
+  return fuse?.search(text.value).map((item) => item.item) || [];
 });
 
 watch(