FIX: github onebox styles for commits (#25098)

app/assets/stylesheets/common/base/onebox.scss

@@ -480,6 +480,11 @@ pre.onebox code {
   .github-info-container {
     width: 100%;
     overflow-x: hidden;
+    > span {
+      // TODO: remove in a few months
+      // replaced by .github-info in new commit oneboxes
+      grid-area: info;
+    }
   }
 
   .github-info {

lib/onebox/templates/githubpullrequest.mustache

@@ -29,6 +29,7 @@
         <a href="{{link}}" target="_blank" rel="noopener">{{commit.message.lines.first}}</a>
       </h4>
 
+      <div class="github-info">
         <span>
           Commit by
           <a href="{{author.html_url}}" target="_blank" rel="noopener">
@@ -38,6 +39,7 @@
           in
           <a href="{{link}}" target="_blank" rel="noopener">{{title}}</a>
         </span>
+      </div>
     {{/commit}}
 
     {{#comment}}