tools: Use parallel building in semaphore (#6330)
tools: Use parallel building in semaphore (#6330)

Make use of the two cores semaphore gives us to speed up the build.
Don't parallelize as aggressively as running the tests though, as some
builds (webpack etc.) take a lot of memory.
andreasn/cockpit,dperpeet/cockpit,moraleslazaro/cockpit,stefwalter/cockpit,SotolitoLabs/cockpit,larskarlitski/cockpit,Scribery/cockpit,moraleslazaro/cockpit,larsu/cockpit,larskarlitski/cockpit,cockpituous/cockpit,harishanand95/cockpit,cockpituous/cockpit,martinpitt/cockpit,Scribery/cockpit,cockpit-project/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,dperpeet/cockpit,mareklibra/cockpit,andreasn/cockpit,SotolitoLabs/cockpit,michalskrivanek/cockpit,stefwalter/cockpit,petervo/cockpit,xhad/cockpit,mareklibra/cockpit,petervo/cockpit,cockpituous/cockpit,martinpitt/cockpit,xhad/cockpit,mvollmer/cockpit,Scribery/cockpit,garrett/cockpit,cockpituous/cockpit,dperpeet/cockpit,petervo/cockpit,larskarlitski/cockpit,deryni/cockpit,dperpeet/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,larsu/cockpit,deryni/cockpit,dperpeet/cockpit,harishanand95/cockpit,Scribery/cockpit,Scribery/cockpit,petervo/cockpit,stefwalter/cockpit,xhad/cockpit,stefwalter/cockpit,larskarlitski/cockpit,SotolitoLabs/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,martinpitt/cockpit,larsu/cockpit,larsu/cockpit,petervo/cockpit,harishanand95/cockpit,deryni/cockpit,cockpit-project/cockpit,mvollmer/cockpit,larskarlitski/cockpit,moraleslazaro/cockpit,Scribery/cockpit,larskarlitski/cockpit,andreasn/cockpit,garrett/cockpit,dperpeet/cockpit,michalskrivanek/cockpit,harishanand95/cockpit,michalskrivanek/cockpit,dperpeet/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,martinpitt/cockpit,larsu/cockpit,stefwalter/cockpit,michalskrivanek/cockpit,xhad/cockpit,michalskrivanek/cockpit,mvollmer/cockpit,xhad/cockpit,xhad/cockpit,cockpit-project/cockpit,harishanand95/cockpit,mareklibra/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,petervo/cockpit,andreasn/cockpit,xhad/cockpit,petervo/cockpit,deryni/cockpit,mvollmer/cockpit,mareklibra/cockpit,SotolitoLabs/cockpit,Scribery/cockpit,mareklibra/cockpit,larsu/cockpit,garrett/cockpit,cockpit-project/cockpit,deryni/cockpit,mareklibra/cockpit,SotolitoLabs/cockpit,michalskrivanek/cockpit,martinpitt/cockpit,mvollmer/cockpit,cockpit-project/cockpit,harishanand95/cockpit,garrett/cockpit,deryni/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,andreasn/cockpit,michalskrivanek/cockpit,mareklibra/cockpit,larskarlitski/cockpit,garrett/cockpit,harishanand95/cockpit,deryni/cockpit