chore: build with Go 1.26; use Go 1.25 features (#10570)

WaitGroup.Go and built-in gomaxprocs handling.

Signed-off-by: Jakob Borg <jakob@kastelo.net>

lib/connections/connections_test.go

@@ -337,23 +337,20 @@ func BenchmarkConnections(b *testing.B) {
 						b.ResetTimer()
 						for i := 0; i < b.N; i++ {
 							var wg sync.WaitGroup
-							wg.Add(2)
 							errC := make(chan error, 2)
-							go func() {
+							wg.Go(func() {
 								if _, err := client.Write(data); err != nil {
 									errC <- err
 									return
 								}
-								wg.Done()
-							}()
-							go func() {
+							})
+							wg.Go(func() {
 								if _, err := io.ReadFull(server, data); err != nil {
 									errC <- err
 									return
 								}
 								total += sz
-								wg.Done()
-							}()
+							})
 							wg.Wait()
 							close(errC)
 							err := <-errC

lib/connections/service.go

@@ -605,15 +605,13 @@ func (s *service) dialDevices(ctx context.Context, now time.Time, cfg config.Con
 		dialWG.Wait()
 		dialCancel()
 	}()
-	for i := range queue {
+	for _, entry := range queue {
 		select {
 		case <-dialCtx.Done():
 			return
 		default:
 		}
-		dialWG.Add(1)
-		go func(entry dialQueueEntry) {
-			defer dialWG.Done()
+		dialWG.Go(func() {
 			conn, ok := s.dialParallel(dialCtx, entry.id, entry.targets, dialSemaphore)
 			if !ok {
 				return
@@ -630,7 +628,7 @@ func (s *service) dialDevices(ctx context.Context, now time.Time, cfg config.Con
 				}
 			}
 			numConnsMut.Unlock()
-		}(queue[i])
+		})
 	}
 }
 
@@ -1118,12 +1116,8 @@ func (s *service) dialParallel(ctx context.Context, deviceID protocol.DeviceID,
 		wg := sync.WaitGroup{}
 		for _, tgt := range tgts {
 			sema.Take(1)
-			wg.Add(1)
-			go func(tgt dialTarget) {
-				defer func() {
-					wg.Done()
-					sema.Give(1)
-				}()
+			wg.Go(func() {
+				defer sema.Give(1)
 				conn, err := tgt.Dial(ctx)
 				if err == nil {
 					// Closes the connection on error
@@ -1136,7 +1130,7 @@ func (s *service) dialParallel(ctx context.Context, deviceID protocol.DeviceID,
 					l.Debugln("dialing", deviceID, tgt.uri, "success:", conn)
 					res <- conn
 				}
-			}(tgt)
+			})
 		}
 
 		// Spawn a routine which will unblock main routine in case we fail