Remove pages_serve_from_legacy_storage feature flag

It's superseeded by Settings.pages.local_storage.enabled

app/models/pages/lookup_path.rb

@@ -62,17 +62,16 @@ module Pages
       }
     end
 
+    # TODO: remove support for legacy storage in 14.3 https://gitlab.com/gitlab-org/gitlab/-/issues/328712
+    # we support this till 14.3 to allow people to still use legacy storage if something goes very wrong
+    # on self-hosted installations, and we'll need some time to fix it
     def legacy_source
-      raise LegacyStorageDisabledError unless Feature.enabled?(:pages_serve_from_legacy_storage, default_enabled: true)
+      return unless ::Settings.pages.local_store.enabled
 
       {
         type: 'file',
         path: File.join(project.full_path, 'public/')
       }
-    rescue LegacyStorageDisabledError => e
-      Gitlab::ErrorTracking.track_exception(e, project_id: project.id)
-
-      nil
     end
   end
 end

app/models/pages/virtual_domain.rb

@@ -21,9 +21,7 @@ module Pages
         project.pages_lookup_path(trim_prefix: trim_prefix, domain: domain)
       end
 
-      # TODO: remove in https://gitlab.com/gitlab-org/gitlab/-/issues/297524
-      # source can only be nil if pages_serve_from_legacy_storage FF is disabled
-      # we can remove this filtering once we remove legacy storage
+      # TODO: remove in https://gitlab.com/gitlab-org/gitlab/-/issues/328715
       paths = paths.select(&:source)
 
       paths.sort_by(&:prefix).reverse

changelogs/unreleased/297524-disable-serving-pages-from-legacy-storage-2.yml

+---
+title: Remove pages_serve_from_legacy_storage feature flag
+merge_request: 60010
+author:
+type: added

config/feature_flags/development/pages_serve_from_legacy_storage.yml

----
-name: pages_serve_from_legacy_storage
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/issues/297228
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/297524
-milestone: '13.8'
-type: development
-group: group::release
-default_enabled: true

spec/models/pages/lookup_path_spec.rb

@@ -52,11 +52,8 @@ RSpec.describe Pages::LookupPath do
       expect(source[:path]).to eq(project.full_path + "/public/")
     end
 
-    it 'return nil when legacy storage is disabled and there is no deployment' do
-      stub_feature_flags(pages_serve_from_legacy_storage: false)
-      expect(Gitlab::ErrorTracking).to receive(:track_exception)
-                                         .with(described_class::LegacyStorageDisabledError, project_id: project.id)
-                                         .and_call_original
+    it 'return nil when local storage is disabled and there is no deployment' do
+      allow(Settings.pages.local_store).to receive(:enabled).and_return(false)
 
       expect(source).to eq(nil)
     end