FIX: Update optionalRequire paths after admin directory move (#35551)

Looks like the admin directory move (#35322) caused a couple issues with
optionalRequire paths, this updates the paths to get the tag admin
dropdown and review queue IP lookup working again.

frontend/discourse/app/components/reviewable-item.gjs

@@ -252,7 +252,7 @@ export default class ReviewableItem extends Component {
   }
 
   get IpLookupComponent() {
-    return optionalRequire("admin/components/ip-lookup");
+    return optionalRequire("discourse/admin/components/ip-lookup");
   }
 
   @bind

frontend/discourse/app/controllers/tags/index.js

@@ -26,7 +26,7 @@ export default class TagsIndexController extends Controller {
   }
 
   get TagsAdminDropdownComponent() {
-    return optionalRequire("admin/components/tags-admin-dropdown");
+    return optionalRequire("discourse/admin/components/tags-admin-dropdown");
   }
 
   @discourseComputed("groupedByCategory", "groupedByTagGroup")

spec/system/tags_index_spec.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+describe "Tags index page", type: :system do
+  fab!(:admin)
+  fab!(:user)
+
+  context "when visiting as a staff user" do
+    it "shows the admin dropdown" do
+      sign_in(admin)
+      visit("/tags")
+
+      expect(page).to have_css(".tags-admin-dropdown")
+    end
+  end
+
+  context "when visiting as a regular user" do
+    it "does not show the admin dropdown" do
+      sign_in(user)
+      visit("/tags")
+
+      expect(page).to have_css(".tags-index")
+      expect(page).to have_no_css(".tags-admin-dropdown")
+    end
+  end
+end