Fix typo in pipeline serializer specs

spec/serializers/pipeline_serializer_spec.rb

@@ -52,7 +52,7 @@ describe PipelineSerializer do
         expect(serializer).to be_paginated
       end
 
-      context 'when resource does is not paginatable' do
+      context 'when resource is not paginatable' do
         context 'when a single pipeline object is being serialized' do
           let(:resource) { create(:ci_empty_pipeline) }
           let(:pagination) { { page: 1, per_page: 1 } }