Remove feature flag for async pipeline processing [RUN ALL RSPEC] [RUN AS-IF-FOSS]

changelogs/unreleased/ci-remove-ff-for-pipeline-async-processing-326217.yml

+---
+title: Move initial pipeline processing to Sidekiq
+merge_request: 58901
+author:
+type: changed

config/feature_flags/development/ci_async_initial_pipeline_processing.yml

----
-name: ci_async_initial_pipeline_processing
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/57589
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/326217
-milestone: '13.11'
-type: development
-group: group::continuous integration
-default_enabled: false

lib/gitlab/ci/pipeline/chain/pipeline/process.rb

@@ -8,11 +8,7 @@ module Gitlab
           # After pipeline has been successfully created we can start processing it.
           class Process < Chain::Base
             def perform!
-              if ::Feature.enabled?(:ci_async_initial_pipeline_processing, project, default_enabled: :yaml)
               ::Ci::InitialPipelineProcessWorker.perform_async(pipeline.id)
-              else
-                ::Ci::ProcessPipelineService.new(pipeline).execute
-              end
             end
 
             def break?

spec/lib/gitlab/ci/pipeline/chain/pipeline/process_spec.rb

@@ -23,21 +23,6 @@ RSpec.describe Gitlab::Ci::Pipeline::Chain::Pipeline::Process do
 
       perform
     end
-
-    context 'with async processing disabled' do
-      before do
-        stub_feature_flags(ci_async_initial_pipeline_processing: false)
-      end
-
-      it 'processes pipeline inline' do
-        expect(::Ci::ProcessPipelineService)
-          .to receive(:new)
-          .with(pipeline)
-          .and_call_original
-
-        perform
-      end
-    end
   end
 
   describe '#break?' do