checkout@v4 breaks subsequent report-size-deltas action

[tfry-git]

Frankly, I do not understand too much about github actions. At any rate, upgrading to checkout@v3 causes our workflow to break at the subsequent report-size-deltas action: https://github.com/sensorium/Mozzi/actions/runs/6611856414/job/17956966682 .

This is definitely not just a coincidental breakage, as we had already merge a prior dependabot pull request, then reverted it, and observed exactly the pattern that report-size-deltas works with checkout@v3, but breaks with checkout@v4.