Remove ci_resource_group_process_modes feature flag

This commit removes the feature flag as it's
deemed stable.

Changelog: added

app/models/ci/resource_group.rb

@@ -32,7 +32,7 @@ module Ci
     end
 
     def upcoming_processables
-      if unordered? || Feature.disabled?(:ci_resource_group_process_modes, project, default_enabled: :yaml)
+      if unordered?
         processables.waiting_for_resource
       elsif oldest_first?
         processables.waiting_for_resource_or_upcoming

config/feature_flags/development/ci_resource_group_process_modes.yml

----
-name: ci_resource_group_process_modes
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/67015
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/340380
-milestone: '14.3'
-type: development
-group: group::release
-default_enabled: false

doc/ci/resource_groups/index.md

@@ -66,13 +66,9 @@ Only one resource can be attached to a resource group.
 
 ## Process modes
 
-> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/202186) in GitLab 14.3.
-
-FLAG:
-On self-managed GitLab, by default this feature is not available.
-To make it available, ask an administrator to [enable the `ci_resource_group_process_modes` flag](../../administration/feature_flags.md).
-On GitLab.com, this feature is not available.
-The feature is not ready for production use.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/202186) in GitLab 14.3.
+> - [Feature flag `ci_resource_group_process_modes`](https://gitlab.com/gitlab-org/gitlab/-/issues/340380) removed in GitLab 14.4.
+> - [Generally available](https://gitlab.com/gitlab-org/gitlab/-/issues/202186) in GitLab 14.4.
 
 You can choose a process mode to strategically control the job concurrency for your deployment preferences.
 The following modes are supported:

lib/api/ci/resource_groups.rb

@@ -32,7 +32,6 @@ module API
                                   values: ::Ci::ResourceGroup.process_modes.keys
         end
         put ':id/resource_groups/:key' do
-          not_found! unless ::Feature.enabled?(:ci_resource_group_process_modes, user_project, default_enabled: :yaml)
           authorize! :update_resource_group, resource_group
 
           if resource_group.update(declared_params(include_missing: false))

spec/models/ci/resource_group_spec.rb

@@ -117,14 +117,6 @@ RSpec.describe Ci::ResourceGroup do
         expect(subject[3]).to eq(build_2_waiting_for_resource)
         expect(subject[4..5]).to contain_exactly(build_2_created, build_2_scheduled)
       end
-
-      context 'when ci_resource_group_process_modes feature flag is disabled' do
-        it 'returns correct jobs in an indeterministic order' do
-          stub_feature_flags(ci_resource_group_process_modes: false)
-
-          expect(subject).to contain_exactly(build_1_waiting_for_resource, build_2_waiting_for_resource)
-        end
-      end
     end
 
     context 'when process mode is newest_first' do
@@ -136,14 +128,6 @@ RSpec.describe Ci::ResourceGroup do
         expect(subject[3]).to eq(build_1_waiting_for_resource)
         expect(subject[4..5]).to contain_exactly(build_1_created, build_1_scheduled)
       end
-
-      context 'when ci_resource_group_process_modes feature flag is disabled' do
-        it 'returns correct jobs in an indeterministic order' do
-          stub_feature_flags(ci_resource_group_process_modes: false)
-
-          expect(subject).to contain_exactly(build_1_waiting_for_resource, build_2_waiting_for_resource)
-        end
-      end
     end
 
     context 'when process mode is unknown' do

spec/requests/api/ci/resource_groups_spec.rb

@@ -62,18 +62,6 @@ RSpec.describe API::Ci::ResourceGroups do
       expect(json_response['process_mode']).to eq('oldest_first')
     end
 
-    context 'when ci_resource_group_process_modes feature flag is disabled' do
-      before do
-        stub_feature_flags(ci_resource_group_process_modes: false)
-      end
-
-      it 'returns not found' do
-        subject
-
-        expect(response).to have_gitlab_http_status(:not_found)
-      end
-    end
-
     context 'with invalid parameter' do
       let(:params) { { process_mode: :unknown } }