fix(ci): add release/* to .build_rules (promote ran without build → not found)
ROOT CAUSE of release/el-salvador promote failures (pipeline #4959, job 28023). .build_rules missing $CI_COMMIT_BRANCH =~ /^release// — build:image not created on release branches, but promote:image ran → candidate not found. The !184 (merged) intent was to add release/* to BOTH rules; build_rules lost it during merge.