SKT Pipeline: Use test_plan_missing to flag tests missing
Pipelines running SKT do not generate a test plan, so it's not possible for DataWarehouse to know when all tests finished.
Setting test_plan_missing=True until we have SKT results will allow DW to consider builds as unfinished until there are test results.
For UPT pipelines, test_plan_missing is set to False in the setup stage, when the test plan is generated.
Should fix umb-messenger#20 (closed)