This reverts commit 032d4a20f9.
The `if not to_cancel: return` was a red herring as what actually matters
is the job status, which is checked in each cancel_job() call, so we
can't know in advance whether anything will be cancelled, so let's just
drop this text explanation.
In the meantime we've also improved the emoji next to cancelled jobs, so
let's hope there is no longer any need to explain what this long list of
job names means.
Fixes: 032d4a20f9 ("bin/ci_run_n_monitor: explain that the 'Universal Recycling symbol' ♲ emoji means these jobs were cancelled")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30265>