_posix_cron_script_argv fell back to sys.executable when the selected venv's
interpreter was gone. On a managed-store install that is the bare store Python,
so the run logged a warning and then died with the same ModuleNotFoundError as
#123044. A half-deleted venv reaches this branch because _recorded_venv only
checks pyvenv.cfg. Raise instead; _run_job_script's try reports it as a failed
run naming the missing interpreter, matching how a broken PM record is handled.
The existing broken-selection test is parametrized over both causes.
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