*: stop using deprecated getWorkflowById

This was deprectated because we don't have get*ById for other modules
and tools, we just use OFS API. This should also be slightly faster
because one less method call (and one less call to warning)
5 jobs for fix/getWorkflowById in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-TestRunner1

00:56:12

running ERP5.CodingStyleTest-TestRunner1

19544:16:50

passed ERP5.PerformanceTest-TestRunner1

00:25:52

failed ERP5.UnitTest-TestRunner1

01:44:20

running ERP5.UnitTest-TestRunner1

19544:16:50