Unexpected GitHub username prompt when vendoring component with invalid URL

[j4zzcat]

Describe the Bug

Unexpected GitHub Username Prompt When Vendoring Component With Invalid URL.

Summary

When running atmos vendor pull on a component that contains an invalid GitHub URL, Atmos unexpectedly prompts for a GitHub username instead of reporting that the URL is incorrect.

This leads to misleading authentication prompts rather than a clear error indicating that the repository cannot be found.

Expected Behavior

Report wrong url.

Steps to Reproduce

Place the following component.yaml in <some dir>.
Then, atmos vendor pull -c <some dir>

component.yaml:

apiVersion: atmos/v1
kind: ComponentVendorConfig
spec:
  source:
    uri: github.com/cloudposse-terraform-components/aws-ec2-XXX.git//src?ref={{ .Version }}
    version: v1.537.0
    included_paths:
      - "**/**"
    excluded_paths: []


### Screenshots

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### Environment

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### Additional Context

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