Feature request: `--multiply-time-limit-by` flag to quickly test a task on old PC

[wil93]

Context: I'm testing some tasks on an old PC, and I mostly just want to make sure that the annotations (// @check-accepted, // @check-time-limit-exceeded, etc) are correct.

I have to manually edit the task.yaml file to avoid some AC solutions being misclassified as TLE. If I could pass this flag it would speed up the process.

Related, I currently run TMR on multiple tasks like so:

$ for i in */; do cd $; task-maker-rust; cd ..; done

Is there a command that does that automatically? Maybe even reading the task list from contest.yaml