E2E tests use repeated strings for test data where constants add no value (#97)

---------

Co-authored-by: Pasha Sviderski <me@psviderski.name>
Co-authored-by: Anton Ovchinnikov <anton@tonyo.info>

pkg/client/dns.go

@@ -4,6 +4,11 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
+	"net/http"
+	"sync"
+	"time"
+
 	"github.com/cenkalti/backoff/v4"
 	"github.com/docker/compose/v2/pkg/progress"
 	"github.com/psviderski/uncloud/internal/machine/api/pb"
@@ -11,10 +16,6 @@ import (
 	"github.com/psviderski/uncloud/pkg/api"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
-	"io"
-	"net/http"
-	"sync"
-	"time"
 )
 
 // GetDomain returns the cluster domain name or ErrNotFound if it hasn't been reserved yet.