Restict type

Co-authored-by: Jan Beinke <git@janbeinke.com>

src/Quasar/Async/STMHelper.hs

@@ -33,7 +33,7 @@ startShortIO fn (TIOWorker jobQueue) exChan = do
           failAsyncVar_ resultVar $ toException $ AsyncException ex
         Right result -> putAsyncVar_ resultVar result
 
-startShortIO_ :: forall a. ShortIO a -> TIOWorker -> ExceptionChannel -> STM ()
+startShortIO_ :: ShortIO () -> TIOWorker -> ExceptionChannel -> STM ()
 startShortIO_ x y z = void $ startShortIO x y z