Update .gitlab-ci.yml

1 job for master in 17 seconds (queued for 2 seconds)
Name Stage Failure
failed
build Test
$ apt install openjfx

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package openjfx
ERROR: Job failed: exit code 1