Remove ci_job_trace_force_encode feature flag

This feature flag was enabled by default in GitLab 14.1, so we can drop
this now.

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/333452

Changelog: changed

app/models/ci/build_trace_chunks/fog.rb

@@ -80,12 +80,10 @@ module Ci
       private
 
       def append_strings(old_data, new_data)
-        if Feature.enabled?(:ci_job_trace_force_encode, default_enabled: :yaml)
         # When object storage is in use, old_data may be retrieved in UTF-8.
         old_data = old_data.force_encoding(Encoding::ASCII_8BIT)
         # new_data should already be in ASCII-8BIT, but just in case it isn't, do this.
         new_data = new_data.force_encoding(Encoding::ASCII_8BIT)
-        end
 
         old_data + new_data
       end

config/feature_flags/development/ci_job_trace_force_encode.yml

----
-name: ci_job_trace_force_encode
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/64631
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/333452
-milestone: '14.1'
-type: development
-group: group::verify
-default_enabled: true

spec/models/ci/build_trace_chunks/fog_spec.rb

@@ -107,7 +107,6 @@ RSpec.describe Ci::BuildTraceChunks::Fog do
     let(:model) { create(:ci_build_trace_chunk, :fog_with_data, initial_data: initial_data) }
     let(:data) { data_store.data(model) }
 
-    context 'when ci_job_trace_force_encode is enabled' do
     it 'appends ASCII data' do
       data_store.append_data(model, +'hello world', 4)
 
@@ -134,25 +133,6 @@ RSpec.describe Ci::BuildTraceChunks::Fog do
     end
   end
 
-    context 'when ci_job_trace_force_encode is disabled' do
-      before do
-        stub_feature_flags(ci_job_trace_force_encode: false)
-      end
-
-      it 'appends ASCII data' do
-        data_store.append_data(model, +'hello world', 4)
-
-        expect(data.encoding).to eq(Encoding::ASCII_8BIT)
-        expect(data.force_encoding(Encoding::UTF_8)).to eq('😺hello world')
-      end
-
-      it 'throws an exception when appending UTF-8 data' do
-        expect(Gitlab::ErrorTracking).to receive(:track_and_raise_exception).and_call_original
-        expect { data_store.append_data(model, +'Résumé', 4) }.to raise_exception(Encoding::CompatibilityError)
-      end
-    end
-  end
-
   describe '#delete_data' do
     subject { data_store.delete_data(model) }