Try to find GitHub action that will let us throttle tests

[plocket]

If we do it in a GitHub action, it will

1. Be easier to test without adding new code to every single test
2. Avoid doubling our test time in one job

For this issue, don't worry about solving all the errors that come up. This is just for finding the action.

• Add the link to the action in this issue
• If you create a new branch, add a link to the new branch in this issue