Remove URL generation rails patch

This change removes the URL generation performance patch which was
upstreamed to Rails 6.1.

config/initializers/action_dispatch_journey_formatter.rb

-# frozen_string_literal: true
-
-# TODO: Eliminate this file when https://github.com/rails/rails/pull/38184 is released.
-# Cleanup issue: https://gitlab.com/gitlab-org/gitlab/issues/195841
-ActionDispatch::Journey::Formatter.prepend(Gitlab::Patch::ActionDispatchJourneyFormatter)
-
-module ActionDispatch
-  module Journey
-    module Path
-      class Pattern
-        def requirements_for_missing_keys_check
-          @requirements_for_missing_keys_check ||= requirements.transform_values do |regex|
-            /\A#{regex}\Z/
-          end
-        end
-      end
-    end
-  end
-end

lib/gitlab/patch/action_dispatch_journey_formatter.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module Patch
-    module ActionDispatchJourneyFormatter
-      def self.prepended(mod)
-        mod.alias_method(:old_missing_keys, :missing_keys)
-        mod.remove_method(:missing_keys)
-      end
-
-      private
-
-      def missing_keys(route, parts)
-        missing_keys = nil
-        tests = route.path.requirements_for_missing_keys_check
-        route.required_parts.each do |key|
-          case tests[key]
-          when nil
-            unless parts[key]
-              missing_keys ||= []
-              missing_keys << key
-            end
-          else
-            unless tests[key].match?(parts[key])
-              missing_keys ||= []
-              missing_keys << key
-            end
-          end
-        end
-        missing_keys
-      end
-    end
-  end
-end

spec/lib/gitlab/patch/action_dispatch_journey_formatter_spec.rb

-# frozen_string_literal: true
-
-require 'spec_helper'
-
-RSpec.describe Gitlab::Patch::ActionDispatchJourneyFormatter do
-  let(:group) { create(:group) }
-  let(:project) { create(:project, namespace: group) }
-  let(:pipeline) { create(:ci_empty_pipeline, project: project) }
-  let(:url) { Gitlab::Routing.url_helpers.project_pipeline_url(project, pipeline) }
-  let(:expected_path) { "#{project.full_path}/-/pipelines/#{pipeline.id}" }
-
-  context 'custom implementation of #missing_keys' do
-    before do
-      expect_any_instance_of(Gitlab::Patch::ActionDispatchJourneyFormatter).to receive(:missing_keys)
-    end
-
-    it 'generates correct url' do
-      expect(url).to end_with(expected_path)
-    end
-  end
-
-  context 'original implementation of #missing_keys' do
-    before do
-      allow_any_instance_of(Gitlab::Patch::ActionDispatchJourneyFormatter).to receive(:missing_keys) do |instance, route, parts|
-        instance.send(:old_missing_keys, route, parts) # test the old implementation
-      end
-    end
-
-    it 'generates correct url' do
-      expect(url).to end_with(expected_path)
-    end
-  end
-end