feat: set step loops with expression variable

step_request.go

@@ -25,6 +25,7 @@ import (
 	"github.com/httprunner/httprunner/v5/internal/httpstat"
 	"github.com/httprunner/httprunner/v5/internal/json"
 	"github.com/httprunner/httprunner/v5/uixt/option"
+	"github.com/httprunner/httprunner/v5/uixt/types"
 )
 
 type HTTPMethod string
@@ -559,7 +560,9 @@ func (s *StepRequest) HTTP2() *StepRequest {
 
 // Loop specify running times for the current step
 func (s *StepRequest) Loop(times int) *StepRequest {
-	s.Loops = times
+	s.Loops = &types.IntOrString{
+		IntValue: &times,
+	}
 	return s
 }