add missing mock

Author: peterargue

engine/access/state_stream/backend/backend_executiondata_test.go

@@ -200,6 +200,7 @@ func (s *BackendExecutionDataSuite) SetupTestMocks() {
 
 	s.state.On("Params").Return(s.params).Maybe()
 	s.params.On("SporkRootBlockHeight").Return(s.rootBlock.Height, nil).Maybe()
+	s.params.On("SporkRootBlock").Return(s.rootBlock, nil).Maybe()
 	s.headers.On("BlockIDByHeight", s.rootBlock.Height).Return(s.rootBlock.ID(), nil).Maybe()
 
 	s.seals.On("FinalizedSealForBlock", mock.AnythingOfType("flow.Identifier")).Return(