Fix heatmap test (go-gitea#17381) (go-gitea#17383)

Backport go-gitea#17381

integrations/api_user_heatmap_test.go

@@ -8,8 +8,10 @@ import (
 	"fmt"
 	"net/http"
 	"testing"
+	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/timeutil"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -20,6 +22,10 @@ func TestUserHeatmap(t *testing.T) {
 	normalUsername := "user2"
 	session := loginUser(t, adminUsername)
 
+	var fakeNow = time.Date(2011, 10, 20, 0, 0, 0, 0, time.Local)
+	timeutil.Set(fakeNow)
+	defer timeutil.Unset()
+
 	urlStr := fmt.Sprintf("/api/v1/users/%s/heatmap", normalUsername)
 	req := NewRequest(t, "GET", urlStr)
 	resp := session.MakeRequest(t, req, http.StatusOK)