Fix leak in logicalrep_worker_detach().

This runs in a long-lived context, so Valgrind complains about it.
It's not clear to me that very much memory can actually be lost.

Author: Tom Lane <[email protected]>
Discussion: https://postgr.es/m/[email protected]

Author: tglsfdc

src/backend/replication/logical/launcher.c

@@ -790,6 +790,8 @@ logicalrep_worker_detach(void)
 		}
 
 		LWLockRelease(LogicalRepWorkerLock);
+
+		list_free(workers);
 	}
 
 	/* Block concurrent access. */