fix(runner): run bench file teardown before aborting on a bad annotation

[Chemaclass]

🤔 Background

Related #1322

A malformed benchmark annotation aborts bashunit bench with exit 1 from inside call_bench_functions. set_up_before_script has already run at that point, so the file's tear_down_after_script never does and whatever it acquired is leaked.

💡 Changes

• Return the failure to the bench loop instead of exiting from the inner frame, so the file's cleanup block runs, then abort from there.
• The annotation error still stops the whole run with the same message and exit code. A value the runner cannot honour would otherwise measure something other than what the annotation asked for (Malformed benchmark annotations are silently ignored #884).
• The test runner has the same defect through its own @timeout/@retry validation, in a different frame. Filed as A malformed @timeout or @retry aborts the run without running tear_down_after_script #1329 rather than widened into this fix.