Use gl-float-right instead of float-right

Uses the gitlab UI class instead of the bootstrap one
for aligning the KAS version

app/views/admin/dashboard/index.html.haml

@@ -146,7 +146,7 @@
           - if Gitlab::Kas.enabled?
             %p
               = _('GitLab KAS')
-              %span.float-right
+              %span.gl-float-right
                 = Gitlab::Kas.version
 
           = render_if_exists 'admin/dashboard/geo'