DEV: Remove `experimental_topics_filter` setting (#29902)

app/controllers/list_controller.rb

@@ -126,8 +126,6 @@ class ListController < ApplicationController
   end
 
   def filter
-    raise Discourse::NotFound if !SiteSetting.experimental_topics_filter
-
     topic_query_opts = { no_definitions: !SiteSetting.show_category_definitions_in_topic_lists }
 
     %i[page q].each do |key|

spec/rails_helper.rb

@@ -693,7 +693,7 @@ RSpec.configure do |config|
 
       RspecErrorTracker.exceptions.each_with_index do |(path, ex), index|
         lines << "\n"
-        lines << "Error encountered while proccessing #{path}"
+        lines << "Error encountered while processing #{path}"
         lines << "  #{ex.class}: #{ex.message}"
         ex.backtrace.each_with_index do |line, backtrace_index|
           if ENV["RSPEC_EXCLUDE_GEMS_IN_BACKTRACE"]

spec/requests/list_controller_spec.rb

@@ -1321,8 +1321,6 @@ RSpec.describe ListController do
     fab!(:private_message_topic)
     fab!(:topic_in_private_category) { Fabricate(:topic, category: private_category) }
 
-    before { SiteSetting.experimental_topics_filter = true }
-
     it "should not return topics that the user is not allowed to view" do
       sign_in(user)
 
@@ -1345,16 +1343,6 @@ RSpec.describe ListController do
       ).to contain_exactly(topic.id)
     end
 
-    it "should respond with 404 response code when `experimental_topics_filter` site setting has not been enabled" do
-      SiteSetting.experimental_topics_filter = false
-
-      sign_in(user)
-
-      get "/filter.json"
-
-      expect(response.status).to eq(404)
-    end
-
     it "returns category definition topics if `show_category_definitions_in_topic_lists` site setting is enabled" do
       category_topic = Fabricate(:topic, category: category)
       category.update!(topic: category_topic)

spec/system/filtering_topics_spec.rb

@@ -6,28 +6,20 @@ describe "Filtering topics", type: :system do
   let(:topic_query_filter) { PageObjects::Components::TopicQueryFilter.new }
   let(:sidebar) { PageObjects::Components::NavigationMenu::Sidebar.new }
 
-  before { SiteSetting.experimental_topics_filter = true }
-
   it "updates the input field when the query string is changed" do
     sidebar_section = Fabricate(:sidebar_section, user: user)
 
-    sidebar_section_link_1 =
     Fabricate(
       :sidebar_section_link,
       sidebar_section: sidebar_section,
       linkable: Fabricate(:sidebar_url, name: "filter tags", value: "/filter?q=tag%3Atag1"),
     )
 
-    sidebar_section_link_2 =
     Fabricate(
       :sidebar_section_link,
       sidebar_section: sidebar_section,
       linkable:
-          Fabricate(
-            :sidebar_url,
-            name: "filter categories",
-            value: "/filter?q=category%3Acategory1",
-          ),
+        Fabricate(:sidebar_url, name: "filter categories", value: "/filter?q=category%3Acategory1"),
     )
 
     sign_in(user)