Enable gitaly_post_upload_pack by default

changelogs/unreleased/post-upload-pack-opt-out.yml

+---
+title: Enable gitaly_post_upload_pack by default
+merge_request: 13078
+author:

lib/gitlab/workhorse.rb

@@ -35,7 +35,10 @@ module Gitlab
                           when 'git_receive_pack'
                             Gitlab::GitalyClient.feature_enabled?(:post_receive_pack)
                           when 'git_upload_pack'
-                            Gitlab::GitalyClient.feature_enabled?(:post_upload_pack)
+                            Gitlab::GitalyClient.feature_enabled?(
+                              :post_upload_pack,
+                              status: Gitlab::GitalyClient::MigrationStatus::OPT_OUT
+                            )
                           when 'info_refs'
                             true
                           else

spec/lib/gitlab/workhorse_spec.rb

@@ -237,7 +237,8 @@ describe Gitlab::Workhorse, lib: true do
         context 'when action is not enabled by feature flag' do
           it 'does not include Gitaly params in the returned value' do
-            allow(Gitlab::GitalyClient).to receive(:feature_enabled?).with(feature_flag).and_return(false)
+            status_opt_out = Gitlab::GitalyClient::MigrationStatus::OPT_OUT
+            allow(Gitlab::GitalyClient).to receive(:feature_enabled?).with(feature_flag, status: status_opt_out).and_return(false)
             expect(subject).not_to include(gitaly_params)
           end