Remove project_finder_similarity_sort feature flag

This enables the similarity sort

Changelog: added

app/finders/projects_finder.rb

@@ -55,7 +55,7 @@ class ProjectsFinder < UnionFinder
     collection = Project.wrap_with_cte(collection) if use_cte
     collection = filter_projects(collection)
 
-    if params[:sort] == 'similarity' && params[:search] && Feature.enabled?(:project_finder_similarity_sort, current_user)
+    if params[:sort] == 'similarity' && params[:search]
       collection.sorted_by_similarity_desc(params[:search])
     else
       sort(collection)

config/feature_flags/development/project_finder_similarity_sort.yml

----
-name: project_finder_similarity_sort
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/43136
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/263249
-milestone: '13.5'
-type: development
-group: group::threat insights
-default_enabled: false

spec/finders/projects_finder_spec.rb

@@ -31,10 +31,6 @@ RSpec.describe ProjectsFinder do
     let(:use_cte) { true }
     let(:finder) { described_class.new(params: params.merge(use_cte: use_cte), current_user: current_user, project_ids_relation: project_ids_relation) }
 
-    before do
-      stub_feature_flags(project_finder_similarity_sort: false)
-    end
-
     subject { finder.execute }
 
     shared_examples 'ProjectFinder#execute examples' do
@@ -389,10 +385,6 @@ RSpec.describe ProjectsFinder do
             create(:project, :internal, group: group, name: 'projAB', path: 'projAB')
           end
 
-          before do
-            stub_feature_flags(project_finder_similarity_sort: current_user)
-          end
-
           it { is_expected.to eq([internal_project2, internal_project4, internal_project3]) }
         end
       end

spec/graphql/resolvers/projects_resolver_spec.rb

@@ -27,10 +27,6 @@ RSpec.describe Resolvers::ProjectsResolver do
       private_group.add_developer(user)
     end
 
-    before do
-      stub_feature_flags(project_finder_similarity_sort: false)
-    end
-
     context 'when user is not logged in' do
       let(:current_user) { nil }
 
@@ -137,14 +133,8 @@ RSpec.describe Resolvers::ProjectsResolver do
           let(:filters) { { search: 'projA', sort: 'similarity' } }
 
           it 'returns projects in order of similarity to search' do
-            stub_feature_flags(project_finder_similarity_sort: current_user)
-
             is_expected.to eq([named_project3, named_project1, named_project2])
           end
-
-          it 'returns projects in any order if flag is off' do
-            is_expected.to match_array([named_project3, named_project1, named_project2])
-          end
         end
 
         context 'when topics filter is provided' do