Changed parallel GitLab CI jobs to serial

This may have been responsible for sporadic failures in the nightly
builds.
7 jobs for develop in 23 minutes and 3 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build Libmesh
passed #8191
build_libmesh_job

00:11:41

 
  Configure Giraffe
passed #8192
configure_giraffe_job

00:00:11

 
  Build Giraffe
failed #8193
build_giraffe_job

00:11:10

 
  Run Giraffe Serial
skipped #8194
run_giraffe_serial_job
 
  Verify Giraffe Serial
skipped #8195
verify_giraffe_serial_job
 
  Run Giraffe Parallel
skipped #8196
run_giraffe_parallel_job
 
  Verify Giraffe Parallel
skipped #8197
verify_giraffe_parallel_job
 
Name Stage Failure
failed
build_giraffe_job Build Giraffe There is an unknown failure, please try again
       common /scruz/ ta1(lx1,ly1,lz1,lelv)
1
Warning: Named COMMON block ‘scruz’ at (1) shall be of the same size as elsewhere (2880000 vs 960000 bytes)
../../Nek5000/core/prepost.f:2267:20:

common /SCRNS/ u4(2+lxo*lxo*lxo*6*lelt)
1
Warning: Named COMMON block ‘scrns’ at (1) shall be of the same size as elsewhere (2880008 vs 960008 bytes)
ERROR: Job failed: exit status 1