testBusinessTemplate: cancel failed activites at end of test

This prevents one failing test to make all subsequent tests to fail
9 jobs for fix/python3-test-framework in 0 seconds (queued for 1 second)
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-TestRunner1

11:36:34

failed ERP5.PerformanceTest-TestRunner1

00:35:11

canceled ERP5.UnitTest-TestRunner1

12:20:56

passed ERP5.CodingStyleTest-TestRunner1

02:19:47

failed ERP5.PerformanceTest-TestRunner1

03:10:51

passed ERP5.PerformanceTest-TestRunner1

00:34:28

failed ERP5.UnitTest-TestRunner1

07:42:53

failed ERP5.UnitTest-TestRunner1

02:30:48

failed ERP5.UnitTest-TestRunner1

03:26:56