ci: Pipeline should ensure basic installability

Not installing package cause all sorts of issues and running
e.g. a superficial autopkgtests is simple enough to ensure that.
3 jobs for ci-installability in 3 minutes and 30 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
passed #237568
librem5
build_html

00:01:12

 
  Test
passed #237569
librem5
test

00:01:07

 
  Package
passed #237570
librem5
package

00:01:11