gitlab-ci: Split out build commands

7 jobs for master in 7 minutes and 50 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #41315
librem5
build-debian-clang

00:02:30

passed #41313
librem5
build-debian-gcc

00:02:44

passed #41314
librem5
build-debian-gcc-static

00:01:59

passed #41317
librem5
build-debian-package

00:01:47

passed #41316
librem5
build-fedora-gcc

00:02:53

 
  Docs
passed #41318
librem5
build-gtkdoc

00:01:26

 
  Test
passed #41319
librem5
unit-test

00:02:36

40.0%