Don't render empty SDG tag list div

The same way we don't render empty regular tags since commit 4d27bbe.

This way we avoid adding an empty `<div class="sdg-tag-list">` tag,
which might have associated styles (in custom CONSUL installation
styles, for instance) and thus break the layout

app/components/sdg/tag_list_component.rb

@@ -7,6 +7,10 @@ def initialize(record, limit: nil, linkable: true)
     @linkable = linkable
   end
 
+  def render?
+    record.sdg_goals.any? || record.sdg_targets.any?
+  end
+
   private
 
     def goals_list

spec/components/sdg/tag_list_component_spec.rb

@@ -22,6 +22,14 @@
     expect(page).to have_link "target 3.2.1"
   end
 
+  it "does not render when there are no tags" do
+    record = build(:debate, sdg_goals: [], sdg_targets: [])
+
+    render_inline SDG::TagListComponent.new(record)
+
+    expect(page.native.inner_html).to be_empty
+  end
+
   context "when linkable is false" do
     let(:component) { SDG::TagListComponent.new(debate, linkable: false) }