fix(make): allow to parallelize jobs (#1845)

* fix: clean up Makefile dependencies to allow for parallel builds

* refactor: remove old unused backend from Makefile

* fix: finish removing legacy backend, update piper

* fix: I broke llama... I fixed llama

* feat: give the tests and builds a few threads

* fix: ensure libraries are replaced before build, add dropreplace target

* Fix image build workflows