X_DOC_CONFIG_ALLOWANCE_STALE
Means
an entry in DOC_CONFIG_KEY_ALLOWANCES matches nothing in the tree
Typical cause
the page was fixed or deleted and its licence to cite an unknown key outlived it. The list may only shrink by being wrong, so a stale entry is a finding rather than dead weight
Fix
delete the { path, cites } entry the finding names from DOC_CONFIG_KEY_ALLOWANCES in scripts/doc-config-keys.ts