Windows Nodes Cannot Utilize Authenticated Proxies

[HarrisonWAffel]

When setting the HTTPS_PROXY and HTTP_PROXY agent environment variables in the Rancher UI, using an authenticated url will result in windows nodes failing to properly configure the proxy. This will lead to image pull failures for the rke2 runtime image, preventing the node from becoming available. This is due to the use of netsh in the wins install script.

https://github.com/rancher/wins/blob/070f0147403142ba616d09b37bfd696d00a8b3d9/install.ps1#L632-L638

The expected format for an authenticated proxy is http(s)://USERNAME:PASSWORD@HOST:PORT, and netsh will return an error whenever more than 1 colon is found in the value.

We likely need to utilize windows credential manager to properly configure the credentials for a given proxy host, and then strip the authentication info from the environment variables before calling netsh