fix(ci): update rechunk action inputs

[p5]

Have replicated the approach (i.e. rechunking rootless podman image), and it's working.

[p5]

Let's hold on this PR for another hour or two.
I very much want to use rootless builds so we can disable and enable rechunk in a single line, but don't want to risk pushing a build that doesn't allow updates.

Will test this out in my own image and report back.