Revert "Add latest changes from gitlab-org/security/gitlab@12-8-stable-ee"

This reverts commit 51ed9979.

This is being reverted due to not having been released

changelogs/unreleased/security-99-disable-caching-on-api-repo-blobs-raw.yml

----
-title: Disable caching on repo/blobs/[sha]/raw endpoint
-merge_request:
-author:
-type: security

lib/api/repositories.rb

@@ -6,8 +6,6 @@ module API
   class Repositories < Grape::API
     include PaginationParams
 
-    helpers ::API::Helpers::HeadersHelpers
-
     before { authorize! :download_code, user_project }
 
     params do
@@ -67,8 +65,6 @@ module API
       get ':id/repository/blobs/:sha/raw' do
         assign_blob_vars!
 
-        no_cache_headers
-
         send_git_blob @repo, @blob
       end
 

spec/requests/api/repositories_spec.rb

@@ -177,12 +177,6 @@ describe API::Repositories do
         expect(headers['Content-Disposition']).to eq 'inline'
       end
 
-      it_behaves_like 'uncached response' do
-        before do
-          get api(route, current_user)
-        end
-      end
-
       context 'when sha does not exist' do
         it_behaves_like '404 response' do
           let(:request) { get api(route.sub(sample_blob.oid, '123456'), current_user) }

spec/support/shared_examples/uncached_response_shared_examples.rb

-# frozen_string_literal: true
-#
-# Pairs with lib/gitlab/no_cache_headers.rb
-#
-
-RSpec.shared_examples 'uncached response' do
-  it 'defines an uncached header response' do
-    expect(response.headers["Cache-Control"]).to include("no-store", "no-cache")
-    expect(response.headers["Pragma"]).to eq("no-cache")
-    expect(response.headers["Expires"]).to eq("Fri, 01 Jan 1990 00:00:00 GMT")
-  end
-end