The auto-retry-stalled workflow only re-ran a failed build's jobs when
more than 50% succeeded; a run with, e.g., 3/10 green (30%) was left red as
"systemic". Lower MIN_SUCCESS_PERCENT to 30 and make the guard inclusive
(retry when succeeded% >= threshold, i.e. compare with -lt), so a 30% run
is retried while genuinely systemic runs (< 30% green) still stay red.
Comments and the warning message updated to match (>= instead of >).

Signed-off-by: Igor Pecovnik <igor@armbian.com>