common: remove no longer needed synctest helper pkg (#19469)

no longer needed after we fully switched to go1.25 as a min version

Author: taratorio

common/synctest/synctest.go

@@ -19,11 +19,10 @@ package sync
 import (
 	"context"
 	"testing"
+	"testing/synctest"
 
 	"github.com/stretchr/testify/require"
 	"golang.org/x/sync/errgroup"
-
-	"github.com/erigontech/erigon/common/synctest"
 )
 
 func TestEventChannel(t *testing.T) {

polygon/sync/event_channel_test.go

@@ -19,13 +19,13 @@ package sync
 import (
 	"context"
 	"testing"
+	"testing/synctest"
 
 	"github.com/stretchr/testify/require"
 	"golang.org/x/sync/errgroup"
 
 	"github.com/erigontech/erigon/common"
 	"github.com/erigontech/erigon/common/log/v3"
-	"github.com/erigontech/erigon/common/synctest"
 	"github.com/erigontech/erigon/common/testlog"
 	"github.com/erigontech/erigon/execution/p2p"
 )

polygon/sync/tip_events_test.go

@@ -27,6 +27,7 @@ import (
 	"sync"
 	"sync/atomic"
 	"testing"
+	"testing/synctest"
 	"time"
 
 	mapset "github.com/deckarep/golang-set/v2"
@@ -41,7 +42,6 @@ import (
 	"github.com/erigontech/erigon/common"
 	"github.com/erigontech/erigon/common/crypto"
 	"github.com/erigontech/erigon/common/log/v3"
-	"github.com/erigontech/erigon/common/synctest"
 	"github.com/erigontech/erigon/common/testlog"
 	"github.com/erigontech/erigon/execution/abi"
 	"github.com/erigontech/erigon/execution/chain/networkname"