Aspire Publish with container in private GHCR.IO registry

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the bug

I am testing out the Aspire CLI.

I can generate my bicep files, but I have two containers that are pulled from a private Github Container Registry.

When I do Aspire Publish, I get the following error on those containers:

```
[DEBUG] Failed to deploy container-name: Deployment failed: ContainerAppOperationError: Failed to provision revision for container app 'container-name'. Error details: The
following field(s) are either invalid or missing. Field 'template.containers.container-name.image' is invalid with details: 'Invalid value: "ghcr.io/org-name/container-name:0.2.0":
GET https:?scope=repository%org-name%2Fcontainer-name%3Apull&service=ghcr.io: UNAUTHORIZED: authentication required';..
```

I don't see any way I am able to authenticate to this feed on this aspire publish pipeline

### Expected Behavior

_No response_

### Steps To Reproduce

_No response_

### Exceptions (if any)

_No response_

### .NET Version info

_No response_

### Anything else?

_No response_

Start with the Aspire CLI publish flow and trace how container images from private GitHub Container Registry are handled, using the reported unauthorized error as the starting symptom. Determine how authentication is expected to reach the publish pipeline, then verify that Aspire Publish can deploy the referenced private containers successfully.

Written by the indexing model from the issue text.