Simplify trace checksum class and fix typo in specs

lib/gitlab/ci/trace/checksum.rb

@@ -72,9 +72,7 @@ module Gitlab
 
         def trace_size
           strong_memoize(:trace_size) do
-            trace_chunks.reduce(0) do |total, chunk|
-              total + chunk_size(chunk)
-            end
+            trace_chunks.sum { |chunk| chunk_size(chunk) }
           end
         end
 

spec/services/ci/update_build_state_service_spec.rb

@@ -211,7 +211,7 @@ RSpec.describe Ci::UpdateBuildStateService do
         end
       end
 
-      context 'when trace checksum is invalid but the log is seems fine' do
+      context 'when trace checksum is invalid but the log seems fine' do
         let(:params) do
           { output: { checksum: 'crc32:12345678', bytesize: 4 }, state: 'success' }
         end