promql: can now remove regex field from EvalNodeHelper

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

promql/engine.go

@@ -30,7 +30,6 @@ import (
 
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
-	"github.com/grafana/regexp"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/model"
 	"go.opentelemetry.io/otel"
@@ -1080,8 +1079,6 @@ type EvalNodeHelper struct {
 	Dmn map[uint64]labels.Labels
 	// funcHistogramQuantile for classic histograms.
 	signatureToMetricWithBuckets map[string]*metricWithBuckets
-	// label_replace.
-	regex *regexp.Regexp
 
 	lb           *labels.Builder
 	lblBuf       []byte