Drop Jenkinsfile

We run in gitlab-ci now
3 jobs for drop-jenkinsfile in 7 minutes and 19 seconds (queued for 12 minutes and 58 seconds)
Status Job ID Name Coverage
  Build
passed #3548
librem5
build-debian-clang

00:02:48

passed #3547
librem5
build-debian-gcc

00:02:12

24.9%
passed #3549
librem5
build-debian-package

00:02:18