Remove lfs_chunked_encoding feature flag

This has been enabled in GitLab 13.7 already by default. This feature
tells the client that they can use chunked transfers, which may help
avoid request buffering and deal and help with large uploads.

Closes https://gitlab.com/gitlab-org/gitlab/-/issues/285581

app/controllers/repositories/lfs_api_controller.rb

@@ -103,18 +103,13 @@ module Repositories
     end
 
     def upload_headers
-      headers = {
+      {
         Authorization: authorization_header,
         # git-lfs v2.5.0 sets the Content-Type based on the uploaded file. This
         # ensures that Workhorse can intercept the request.
-        'Content-Type': LFS_TRANSFER_CONTENT_TYPE
+        'Content-Type': LFS_TRANSFER_CONTENT_TYPE,
+        'Transfer-Encoding': 'chunked'
       }
-
-      if Feature.enabled?(:lfs_chunked_encoding, project, default_enabled: true)
-        headers['Transfer-Encoding'] = 'chunked'
-      end
-
-      headers
     end
 
     def lfs_check_batch_operation!

changelogs/unreleased/sh-remove-lfs-chunked-encoding-feature-flag.yml

+---
+title: Remove lfs_chunked_encoding feature flag
+merge_request: 50557
+author:
+type: changed

config/feature_flags/development/lfs_chunked_encoding.yml

----
-name: lfs_chunked_encoding
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/48269
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/285581
-milestone: '13.6'
-type: development
-group:
-default_enabled: true

spec/requests/lfs_http_spec.rb

@@ -193,10 +193,8 @@ RSpec.describe 'Git LFS API and storage' do
         subject(:request) { post_lfs_json batch_url(project), body, headers }
 
         let(:response) { request && super() }
-        let(:lfs_chunked_encoding) { true }
 
         before do
-          stub_feature_flags(lfs_chunked_encoding: lfs_chunked_encoding)
           project.lfs_objects << lfs_object
         end
 
@@ -480,20 +478,6 @@ RSpec.describe 'Git LFS API and storage' do
               expect(headers['Transfer-Encoding']).to eq('chunked')
             end
 
-            context 'when lfs_chunked_encoding feature is disabled' do
-              let(:lfs_chunked_encoding) { false }
-
-              it 'responds with upload hypermedia link' do
-                expect(json_response['objects']).to be_kind_of(Array)
-                expect(json_response['objects'].first).to include(sample_object)
-                expect(json_response['objects'].first['actions']['upload']['href']).to eq(objects_url(project, sample_oid, sample_size))
-
-                headers = json_response['objects'].first['actions']['upload']['header']
-                expect(headers['Content-Type']).to eq('application/octet-stream')
-                expect(headers['Transfer-Encoding']).to be_nil
-              end
-            end
-
             it_behaves_like 'process authorization header', renew_authorization: renew_authorization
           end