npm writes its debug logs to _logs inside the cache. Every build adds ~10 files and deletes ~10 (npm keeps the last 10), churn with no caching value that, together with the verify rewrite, stops 1289314 from skipping saves. Details: T435973#12288198.
Change: set logs-dir to an absolute path outside /cache in the global npmrc added by 1335785 (dockerfiles/node24|node26/npmrc), so one change covers Quibble, Wikibase sub-invocations and codehealth.
Once every job runs on the new images, purge the existing _logs from the namespaces on castor06 once. Load restores them, so excluding them from the save alone is not enough.