Allow setting the scheduler for a resource pool

guix-data-service/utils.scm

@@ -110,6 +110,7 @@
                              (duration-logger (const #f))
                              destructor
                              lifetime
+                             scheduler
                              (name "unnamed"))
   (define (initializer/safe)
     (with-exception-handler
@@ -342,7 +343,9 @@
                         available
                         waiters
                         resources-last-used)))))
-           #:unwind? #t))))
+           #:unwind? #t)))
+     (or scheduler
+         (current-scheduler)))
 
     (make-resource-pool-record name channel)))