Flake checker download not found

[ecarlson94]

The nix flake action can't download the checker:

https://fiids.install.determinate.systems/flake-checker/stable/X64-Linux (404 Not Found)

<Error>
    <Code>NoSuchKey</Code>
    <Message>The specified key does not exist.</Message>
    <Key>v0.1.20/flake-checker-X64-Linux</Key>
    <RequestId>TQCQ7DG397XG760N</RequestId>
    <HostId>
        hCU8qc+oP/H9LPCqugJ9O1HIWO7xyhxG0wDTgjsASe6AbP9m4J0WHkH/AiqJSWdbP0nv64gq5E2RO6ZVvxKgEcT2mc5Q2pmVyDIuTdOgPtw=
    </HostId>
</Error>

[lucperkins]

This should be fixed now! Please let us know if not.