Remove isolated useless assignments

These variables are not surrounded by other assignments, and so they can
safely be removed without making it harder to read the code vertically.

spec/features/home_spec.rb

@@ -11,7 +11,7 @@ describe "Home" do
     end
 
     scenario "Not display recommended section" do
-      debate = create(:debate)
+      create(:debate)
 
       visit root_path
 
@@ -32,13 +32,15 @@ describe "Home" do
       end
 
       scenario "Display recommended section when feature flag recommended is active" do
-        debate = create(:debate, tag_list: "Sport")
+        create(:debate, tag_list: "Sport")
+
         visit root_path
+
         expect(page).to have_content "Recommendations that may interest you"
       end
 
       scenario "Not display recommended section when feature flag recommended is not active" do
-        debate = create(:debate, tag_list: "Sport")
+        create(:debate, tag_list: "Sport")
         Setting["feature.user.recommendations"] = false
 
         visit root_path
@@ -56,8 +58,10 @@ describe "Home" do
       end
 
       scenario "Display all recommended debates link" do
-        debate = create(:debate, tag_list: "Sport")
+        create(:debate, tag_list: "Sport")
+
         visit root_path
+
         expect(page).to have_link("All recommended debates", href: debates_path(order: "recommendations"))
       end
 
@@ -71,8 +75,10 @@ describe "Home" do
       end
 
       scenario "Display all recommended proposals link" do
-        debate = create(:proposal, tag_list: "Sport")
+        create(:proposal, tag_list: "Sport")
+
         visit root_path
+
         expect(page).to have_link("All recommended proposals", href: proposals_path(order: "recommendations"))
       end
 
@@ -140,7 +146,7 @@ describe "Home" do
   end
 
   scenario "if there are cards, the 'featured' title will render" do
-    card = create(:widget_card,
+    create(:widget_card,
       title: "Card text",
       description: "Card description",
       link_text: "Link text",