Enable products cache by default only in staging and production

We keep tests running by default without cache, keeping it as it was before 10a79d5a65

Additionally, cached_products_renderer no longer depends on Rails.env, so here we remove that dependency from it's spec.

app/models/spree/app_configuration_decorator.rb

@@ -39,5 +39,5 @@ Spree::AppConfiguration.class_eval do
   preference :enable_localized_number?, :boolean, default: false
 
   # Enable cache
-  preference :enable_products_cache?, :boolean, default: !Rails.env.development?
+  preference :enable_products_cache?, :boolean, default: (Rails.env.production? || Rails.env.staging?)
 end

spec/lib/open_food_network/cached_products_renderer_spec.rb

@@ -27,7 +27,6 @@ module OpenFoodNetwork
 
       context "products cache toggle" do
         before do
-          allow(Rails.env).to receive(:production?) { true }
           Rails.cache.write "products-json-#{distributor.id}-#{order_cycle.id}", 'products'
         end
 
@@ -52,19 +51,9 @@ module OpenFoodNetwork
         end
       end
 
-      context "when in testing / development" do
+      context "products cache enabled" do
         before do
-          allow(Rails.env).to receive(:production?) { false }
-        end
-
-        it "returns uncached products JSON" do
-          expect(cached_products_renderer.products_json).to eq 'uncached products'
-        end
-      end
-
-      context "when in production / staging" do
-        before do
-          allow(Rails.env).to receive(:production?) { true }
+          Spree::Config[:enable_products_cache?] = true
         end
 
         describe "when the distribution is not set" do