chore: update normalize funnel steps

Signed-off-by: Shivanshu Raj Shrivastava <shivanshu1333@gmail.com>

pkg/modules/tracefunnel/utils.go

@@ -48,17 +48,28 @@ func ValidateFunnelSteps(steps []tracefunnel.FunnelStep) error {
 	return nil
 }
 
-// NormalizeFunnelSteps normalizes step orders to be sequential
+// NormalizeFunnelSteps normalizes step orders to be sequential starting from 1.
+// Returns a new slice with normalized step orders, leaving the input slice unchanged.
 func NormalizeFunnelSteps(steps []tracefunnel.FunnelStep) []tracefunnel.FunnelStep {
-	sort.Slice(steps, func(i, j int) bool {
-		return steps[i].Order < steps[j].Order
-	})
-
-	for i := range steps {
-		steps[i].Order = int64(i + 1)
+	if len(steps) == 0 {
+		return nil
 	}
 
-	return steps
+	// Create a copy of the input slice
+	newSteps := make([]tracefunnel.FunnelStep, len(steps))
+	copy(newSteps, steps)
+
+	// Sort the copy
+	sort.Slice(newSteps, func(i, j int) bool {
+		return newSteps[i].Order < newSteps[j].Order
+	})
+
+	// Update orders in the copy
+	for i := range newSteps {
+		newSteps[i].Order = int64(i + 1)
+	}
+
+	return newSteps
 }
 
 func GetClaims(r *http.Request) (*authtypes.Claims, error) {