Remove tag limit feature flag

Changelog: added

config/feature_flags/development/ci_build_tags_limit.yml

----
-name: ci_build_tags_limit
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/68380
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/338929
-milestone: '14.2'
-type: development
-group: group::pipeline execution
-default_enabled: true

lib/gitlab/ci/config/entry/tags.rb

@@ -16,8 +16,6 @@ module Gitlab
             validates :config, array_of_strings: true
 
             validate do
-              next unless ::Feature.enabled?(:ci_build_tags_limit, default_enabled: :yaml)
-
               if config.is_a?(Array) && config.size >= TAGS_LIMIT
                 errors.add(:config, _("must be less than the limit of %{tag_limit} tags") % { tag_limit: TAGS_LIMIT })
               end

spec/lib/gitlab/ci/config/entry/tags_spec.rb

@@ -36,25 +36,9 @@ RSpec.describe Gitlab::Ci::Config::Entry::Tags do
         context 'when tags limit is reached' do
           let(:config) { Array.new(50) {|i| "tag-#{i}" } }
 
-          context 'when ci_build_tags_limit is enabled' do
-            before do
-              stub_feature_flags(ci_build_tags_limit: true)
-            end
-
-            it 'reports error' do
-              expect(entry.errors)
-                .to include "tags config must be less than the limit of #{described_class::TAGS_LIMIT} tags"
-            end
-          end
-
-          context 'when ci_build_tags_limit is disabled' do
-            before do
-              stub_feature_flags(ci_build_tags_limit: false)
-            end
-
-            it 'does not report an error' do
-              expect(entry.errors).to be_empty
-            end
+          it 'reports error' do
+            expect(entry.errors)
+              .to include "tags config must be less than the limit of #{described_class::TAGS_LIMIT} tags"
           end
         end
       end