Use GH token to download Podman release in utils.ps1

This is to avoid requests failing due to GitHub's non-authenticated
request rate limit.

See [this PR check
failure](https://github.com/podman-container-tools/podman-sandbox/actions/runs/26632208486/job/78483599334?pr=5)
for an example of such a failure.

Signed-off-by: Mario Loriedo <mario.loriedo@gmail.com>