Remove disable_composer_callback feature flag

Removes the disable_composer_callback feature flag
and deletes the composer callback that the
feature flag was disabling.

This callback was not working or needed and was
throwing errors.

Changelog: fixed

app/models/packages/package.rb

@@ -158,8 +158,6 @@ class Packages::Package < ApplicationRecord
     joins(:project).reorder(keyset_order)
   end
 
-  after_commit :update_composer_cache, on: :destroy, if: -> { composer? && Feature.disabled?(:disable_composer_callback) }
-
   def self.only_maven_packages_with_path(path, use_cte: false)
     if use_cte
       # This is an optimization fence which assumes that looking up the Metadatum record by path (globally)
@@ -295,12 +293,6 @@ class Packages::Package < ApplicationRecord
 
   private
 
-  def update_composer_cache
-    return unless composer?
-
-    ::Packages::Composer::CacheUpdateWorker.perform_async(project_id, name, composer_metadatum.version_cache_sha) # rubocop:disable CodeReuse/Worker
-  end
-
   def composer_tag_version?
     composer? && !Gitlab::Regex.composer_dev_version_regex.match(version.to_s)
   end

config/feature_flags/development/disable_composer_callback.yml

----
-name: disable_composer_callback
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/64016
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/333587
-milestone: '14.0'
-type: development
-group: group::package
-default_enabled: false

spec/models/packages/package_spec.rb

@@ -1006,37 +1006,4 @@ RSpec.describe Packages::Package, type: :model do
       it_behaves_like 'not enqueuing a sync worker job'
     end
   end
-
-  context 'destroying a composer package' do
-    let_it_be(:package_name) { 'composer-package-name' }
-    let_it_be(:json) { { 'name' => package_name } }
-    let_it_be(:project) { create(:project, :custom_repo, files: { 'composer.json' => json.to_json } ) }
-
-    let!(:package) { create(:composer_package, :with_metadatum, project: project, name: package_name, version: '1.0.0', json: json) }
-
-    before do
-      Gitlab::Composer::Cache.new(project: project, name: package_name).execute
-      package.composer_metadatum.reload
-    end
-
-    context 'with feature flag disabled' do
-      before do
-        stub_feature_flags(disable_composer_callback: false)
-      end
-
-      it 'schedule the update job' do
-        expect(::Packages::Composer::CacheUpdateWorker).to receive(:perform_async).with(project.id, package_name, package.composer_metadatum.version_cache_sha)
-
-        package.destroy!
-      end
-    end
-
-    context 'with feature flag enabled' do
-      it 'does nothing' do
-        expect(::Packages::Composer::CacheUpdateWorker).not_to receive(:perform_async)
-
-        package.destroy!
-      end
-    end
-  end
 end