wkg oci push doesn't work on Windows

[danbugs]

How to repro

> wkg --version
wkg 0.9.0

On Windows WSL

> echo "<gh pat token>" | docker login ghcr.io -u <username> --password-stdin
Login Succeeded
> wkg oci push ghcr.io/<username>/<some name>:<some tag> <path to wasm component>
pushed: ghcr.io/<username>/<some name>:<some tag>
digest: sha256:<something something something>

Works ✅

On Windows PowerShell

> echo "<gh pat token>" | docker login ghcr.io -u <username> --password-stdin
Login Succeeded
> wkg oci push ghcr.io/<username>/<some name>:<some tag> <path to wasm component>
Error: Unable to push image

Caused by:
    Server error: url https://ghcr.io/v2/<username>/<some name>/blobs/uploads/, code: 401, message: {"errors":[{"code":"UNAUTHORIZED","message":"authentication required"}]}

Doesn't work ❎