REVERT: "A11Y: topic list links should not be headings (#27700)" (#29520)

This reverts commit 72a5389459.

app/assets/javascripts/discourse/app/components/topic-list/topic-link.gjs

@@ -13,6 +13,8 @@ export default class TopicLink extends Component {
     <a
       href={{this.url}}
       data-topic-id={{@topic.id}}
+      role="heading"
+      aria-level="2"
       class="title"
       ...attributes
     >{{htmlSafe @topic.fancyTitle}}</a>

app/assets/javascripts/discourse/app/helpers/topic-link.js

@@ -17,6 +17,8 @@ export default function topicLink(topic, args = {}) {
 
   return htmlSafe(
     `<a href='${url}'
+        role='heading'
+        aria-level='2'
         class='${classes.join(" ")}'
         data-topic-id='${topic.id}'>${title}</a>`
   );