Fix footer's link wrapping in Firefox. (#8569)

Author: isoos

pkg/web_css/lib/src/_footer.scss

@@ -15,6 +15,7 @@
   color: var(--pub-footer-text-color);
 
   > a.link {
+    display: inline-block;
     color: var(--pub-footer-text-color);
     padding-right: 12px;
     text-wrap: nowrap;