Remove unnecessary tests

ee/spec/uploaders/job_artifact_uploader_spec.rb

-require 'spec_helper'
-
-describe JobArtifactUploader do
-  let(:store) { ObjectStorage::Store::LOCAL }
-  let(:job_artifact) { create(:ci_job_artifact, file_store: store) }
-  let(:uploader) { described_class.new(job_artifact, :file) }
-
-  describe '#open' do
-    subject { uploader.open }
-
-    context 'when trace is stored in Object storage' do
-      before do
-        allow(uploader).to receive(:file_storage?) { false }
-        allow(uploader).to receive(:url) { 'http://object_storage.com/trace' }
-      end
-
-      it 'returns http io stream' do
-        is_expected.to be_a(Gitlab::Ci::Trace::HttpIO)
-      end
-    end
-  end
-end