src/should.py: do not run at all the commands when unmet !REQUIRES or !NO_LAUNCHER

fix #65
3 jobs for 65-bug-no-launcher in 21 seconds (queued for 9 minutes and 28 seconds)
Status Job ID Name Coverage
  Unit
passed #10332
unit

00:00:06

 
  Demo
passed #10333
demo

00:00:07

 
  Coverage
passed #10334
coverage

00:00:08

86.0%