fix: use comment.metadata.name instead of index as the key of comments list (#830)

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#### What this PR does / why we need it:
修复后台删除评论后会导致下方头像错误的bug
#### Which issue(s) this PR fixes:

Fixes https://github.com/halo-dev/halo/issues/3170
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#### Does this PR introduce a user-facing change?

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```release-note
修复后台删除评论后会导致下方头像错误的bug
```

src/modules/contents/comments/CommentList.vue

@@ -492,7 +492,10 @@ function handleClearFilters() {
           class="box-border h-full w-full divide-y divide-gray-100"
           role="list"
         >
-          <li v-for="(comment, index) in comments.items" :key="index">
+          <li
+            v-for="comment in comments.items"
+            :key="comment.comment.metadata.name"
+          >
             <CommentListItem
               :comment="comment"
               :is-selected="checkSelection(comment)"