Description of the desired feature

The testing workflow usually takes ~10 minutes to run. When we make a new commit to a branch, we usually don't care about if previous commit runs fine or not, and canceling previous runs can save a lot of time and CI resources.

Here is a github action, which can automatically cancel previous runs:

https://github.com/marketplace/actions/cancel-workflow-action

Are you willing to help implement and maintain this feature? Yes, but volunteers are welcomed.