Go 1.26 and golangci-lint updates (#2146)

Keep Go 1.24 compatibility for now (by not using `wg.Go()`).

stackless/func.go

@@ -27,7 +27,7 @@ func NewFunc(f func(ctx any)) func(ctx any) bool {
 	funcWorkCh := make(chan *funcWork, runtime.GOMAXPROCS(-1)*2048)
 	onceInit := func() {
 		n := runtime.GOMAXPROCS(-1)
-		for i := 0; i < n; i++ {
+		for range n {
 			go funcWorker(funcWorkCh, f)
 		}
 	}