* fix: locking around concurrency-1 jobs * fix: no lock on queue duplicates (cherry picked from commit 477452b5c51ca71ecdf74205e0004eaec4e18874)
* fix: locking around concurrency-1 jobs * fix: no lock on queue duplicates (cherry picked from commit 477452b5c51ca71ecdf74205e0004eaec4e18874)