Open footer description links in the same window

This is a funny one, because we were accidentally opening them in the
same window without intending to do so since commit 928312e21, since the
`sanitize` method removes the `target` attribute. So the test we're
adding already passed without these changes.

spec/components/layout/footer_component_spec.rb

@@ -0,0 +1,13 @@
+require "rails_helper"
+
+describe Layout::FooterComponent do
+  describe "description links" do
+    it "generates links that open in the same tab" do
+      render_inline Layout::FooterComponent.new
+
+      page.find(".info") do |info|
+        expect(info).not_to have_css "a[target]"
+      end
+    end
+  end
+end