reduce to 1 job per pipeline

1 job for master in 1 minute and 59 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
failed #46025
fp
build-iris.dev

00:01:59

 
Name Stage Failure
failed
build-iris.dev Build
[coq-stdpp.dev] no changes from git+https://gitlab.mpi-sws.org/iris/stdpp.git#master
[coq-iris.dev] no changes from git+https://gitlab.mpi-sws.org/iris/iris.git#master
[coq.8.10.dev] synchronised from git+https://github.com/coq/coq.git#v8.10

The following dependencies couldn't be met:
- coq -> ocaml >= 4.05.0
base of this switch (use `--unlock-base' to force)

ERROR: Job failed: exit code 1