Even more db.DefaultContext refactor (#27352)

Part of #27065

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: delvh <dev.lh@web.de>

services/attachment/attachment_test.go

@@ -32,7 +32,7 @@ func TestUploadAttachment(t *testing.T) {
 	assert.NoError(t, err)
 	defer f.Close()
 
-	attach, err := NewAttachment(&repo_model.Attachment{
+	attach, err := NewAttachment(db.DefaultContext, &repo_model.Attachment{
 		RepoID:     1,
 		UploaderID: user.ID,
 		Name:       filepath.Base(fPath),