fix test

Signed-off-by: SungJin1212 <tjdwls1201@gmail.com>

Author: SungJin1212

integration/e2e/service.go

@@ -15,6 +15,7 @@ import (
 	"github.com/go-kit/log"
 	"github.com/pkg/errors"
 	"github.com/prometheus/common/expfmt"
+	"github.com/prometheus/common/model"
 	"github.com/thanos-io/thanos/pkg/runutil"
 
 	"github.com/cortexproject/cortex/pkg/util/backoff"
@@ -623,7 +624,7 @@ func (s *HTTPService) SumMetrics(metricNames []string, opts ...MetricsOption) ([
 		return nil, err
 	}
 
-	var tp expfmt.TextParser
+	tp := expfmt.NewTextParser(model.UTF8Validation)
 	families, err := tp.TextToMetricFamilies(strings.NewReader(metrics))
 	if err != nil {
 		return nil, err