build_jobs are not killed on abort

[Blanca-Fuentes]

I think build jobs are not killed on abort

https://github.com/reframe-hpc/reframe/blob/73441fac5598484300c807ce5357e6ff0d24b395/reframe/frontend/executors/init.py#L514-L524

[vkarak]

@Blanca-Fuentes Do you have a reproducer?

[vkarak]

Given the code snippet above that's very likely to happen and it should be reproducible only when running on a cluster. Running the following command and aborting, it should be reproducing it, but I need to verify it:

reframe -c unittests/resources/checks/hellocheck.py -n ^HelloTest -S build_locally=0 -S prebuild_cmds="sleep 30" -r

[vkarak]

I reproduced it in the pseudo-cluster of the tutorial.