Update commit toggle description

MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/40524

app/assets/javascripts/diffs/components/commit_item.vue

@@ -149,14 +149,13 @@ export default {
 
         <span class="commit-row-message d-block d-sm-none">&middot; {{ commit.short_id }}</span>
 
-        <button
+        <gl-button
           v-if="commit.description_html && collapsible"
-          class="text-expander js-toggle-button"
-          type="button"
+          class="js-toggle-button"
+          size="small"
+          icon="ellipsis_h"
           :aria-label="__('Toggle commit description')"
-        >
-          <gl-icon :size="12" name="ellipsis_h" />
-        </button>
+        />
 
         <div class="committer">
           <a

changelogs/unreleased/229336-diffs-collapsible-button.yml

+---
+title: Update commit toggle description button to gl-button
+merge_request: 40524
+author:
+type: changed

spec/frontend/diffs/components/commit_item_spec.js

@@ -24,8 +24,7 @@ describe('diffs/components/commit_item', () => {
 
   const getTitleElement = () => wrapper.find('.commit-row-message.item-title');
   const getDescElement = () => wrapper.find('pre.commit-row-description');
-  const getDescExpandElement = () =>
-    wrapper.find('.commit-content .text-expander.js-toggle-button');
+  const getDescExpandElement = () => wrapper.find('.commit-content .js-toggle-button');
   const getShaElement = () => wrapper.find('.commit-sha-group');
   const getAvatarElement = () => wrapper.find('.user-avatar-link');
   const getCommitterElement = () => wrapper.find('.committer');