[assembly] Make it possible to set number of threads and enable multithreading per default

7 jobs for !2640 with feature/colored-smp-assembly in 17 minutes and 31 seconds (queued for 6 seconds)
Child pipeline (parent) latest detached
Status Name Job ID Coverage
  Configure
passed configure #47297

00:01:42

 
  Linting
passed black (python) #47300

00:00:39

passed pylint-flake8 (python) #47302

00:00:25

 
  Select
passed select tests #47306

00:00:52

 
  Build
passed compile cpp #47308

00:08:46

 
  Test
passed test cpp #47310

00:06:06

passed test python #47312

00:00:34