Change update-circt action to v1 to get updates

Change the version of the update-circt action used when running CD from an
explicit v1.0.0 to v1.  This will cause it to grab minor features and bug
fixes.  Practically, this pulls in a bug fix related to failing to
cherry-pick the staging branch.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@sifive.com>