Use context parameter in models/git (#22367)

After #22362, we can feel free to use transactions without
`db.DefaultContext`.

And there are still lots of models using `db.DefaultContext`, I think we
should refactor them carefully and one by one.

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

services/convert/status.go

@@ -20,7 +20,7 @@ func ToCommitStatus(ctx context.Context, status *git_model.CommitStatus) *api.Co
 		TargetURL:   status.TargetURL,
 		Description: status.Description,
 		ID:          status.Index,
-		URL:         status.APIURL(),
+		URL:         status.APIURL(ctx),
 		Context:     status.Context,
 	}