Merge github copilot cli with codex cli

### Describe the feature or problem you'd like to solve

Contribute to codex cli instead of github copilot cli

### Proposed solution

We are using github copilot with an enterprise usage for almost 400 developers. As a model we mostly use the codex models, currently codex 5.1 max. The issue is that the codex model doesn't perform really well without codex cli, neither with the github copilot cli nor with github copilot vscode extension. We would prefer that github copilot instead of developing its own cli would have the option that we could use the enterprise github copilot license being used to also login with codex cli. Currenlty we are reverting to using azure api keys to use the codex models with codex cli. so we pay for azure and github copilot license... Would be great if you could talk to your openai buddies and make this possible.

### Example prompts or workflows

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### Additional context

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