Remove a spec: validate_uniqueness_of for key

spec/models/ci/pipeline_schedule_variable_spec.rb

@@ -4,5 +4,4 @@ describe Ci::PipelineScheduleVariable, models: true do
   subject { build(:ci_pipeline_schedule_variable) }
 
   it { is_expected.to include_module(HasVariable) }
-  it { is_expected.to validate_uniqueness_of(:key).scoped_to(:pipeline_schedule_id) }
 end