Cancel CI jobs/pipeline when commit becomes unavailable

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After rebasing and force pushing a branch (and possibly git gc?), the old commits become unavailable. Still, there might be pending CI jobs for the old commits which start running later:

gitlab-ci-multi-runner 1.3.3 (6220bd5)
[...]
Checking out a687827a as issue-1225...
fatal: reference is not a tree: a687827a84e97bd3caeafd28d581e40cac423b78

ERROR: Build failed: exit status 1

I think it would make a lot of sense to show those CI jobs/pipelines as canceled. Right now, it leads to many "failed builds".