azure-cli/setup.py depends on PyGithub v1

### Describe the bug

azure-cli requires to import PyGithub v1 which prevents others to install PyGithub v2.

https://github.com/Azure/azure-cli/blob/dev/src/azure-cli/setup.py#L143C6-L143C14

### Related command

N/A

### Errors

N/A

### Issue script & Debug output

N/A

### Expected behavior

We should be able to install the latest version of PyGithub.

### Environment Summary

```
> az --version
azure-cli 2.54.0

core 2.54.0
telemetry 1.1.0

Dependencies:
msal 1.25.0
azure-mgmt-resource 23.1.0b2

Python location '/Users/stephane/.pyenv/versions/3.11.6/bin/python'
Extensions directory '/Users/stephane/.azure/cliextensions'

Python (Darwin) 3.11.6 (main, Oct 6 2023, 15:56:03) [Clang 15.0.0 (clang-1500.0.40.1)]
```

### Additional context

While the preferred method to install the az cli is the official method with the dedicated interepretter and copy of the azure SDK this is not ok for folks that work with ephemeral containers due to the extremely large size of the Azure SDK. Having a duplicate copy of the azure SDK is a big problem that is tracked in other long open issues. We cannot use the official method and the strict import tree of the azure CLI is causing conflicts.