CI: Fix file overlap errors on main
I broke this in h04d28dc6be1cbe4a8d818a7b4852928911c7a24d (part of !2290 (merged)).
I made a demo branch to repro the error. You can see it fail here: https://gitlab.torproject.org/Diziet/arti/-/pipelines/190196
And, I have verified the fix in a mutated version of this branch, here https://gitlab.torproject.org/Diziet/arti/-/pipelines/190193