refactor: replace json with json-iterator/go to improve performance

internal/boomer/output.go

@@ -1,7 +1,6 @@
 package boomer
 
 import (
-	"encoding/json"
 	"fmt"
 	"os"
 	"sort"
@@ -13,6 +12,8 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/push"
 	"github.com/rs/zerolog/log"
+
+	"github.com/httprunner/hrp/internal/json"
 )
 
 // Output is primarily responsible for printing test results to different destinations

internal/boomer/stats.go

@@ -1,8 +1,9 @@
 package boomer
 
 import (
-	"encoding/json"
 	"time"
+
+	"github.com/httprunner/hrp/internal/json"
 )
 
 type transaction struct {