FIX: Use category hashtag instead of link in discourse_welcome_topic.body (#22875)

Linking to the #feedback category can break if the category gets renamed or a different site locale is used. By using the correct hashtag (at the time of seeding) this issues can be avoided.

spec/lib/seed_data/topics_spec.rb

@@ -16,6 +16,9 @@ RSpec.describe SeedData::Topics do
 
   describe "#create" do
     it "creates a missing topic" do
+      staff_category = Fabricate(:category, name: "Feedback")
+      SiteSetting.meta_category_id = staff_category.id
+
       expect { create_topic }.to change { Topic.count }.by(1).and change { Post.count }.by(1)
 
       topic = Topic.last
@@ -29,6 +32,7 @@ RSpec.describe SeedData::Topics do
           site_title: SiteSetting.title,
           site_description: SiteSetting.site_description,
           site_info_quote: "",
+          feedback_category: "#feedback",
         ).rstrip,
       )
       expect(topic.category_id).to eq(SiteSetting.general_category_id)
@@ -133,6 +137,7 @@ RSpec.describe SeedData::Topics do
           site_title: SiteSetting.title,
           site_description: SiteSetting.site_description,
           site_info_quote: "",
+          feedback_category: "#site-feedback",
         ).rstrip,
       )
     end