For GitHub plugins, use scmAuthApi instead of githubAuthApi

[ltdonner-bah]

Feature Suggestion

We have some repositories in a GitHub Enterprise Server instance and some on github.com
For GitHub plugins (in our case the Pull Requests and GitHub Insights plugins) we can only use the plugins for one or the other.
This feature suggestion is to alter how tokens are retrieved in order to be able to use these plugins for multiple GitHub instances.

Possible Implementation

https://github.com/RoadieHQ/roadie-backstage-plugins/blob/main/plugins/frontend/backstage-plugin-github-pull-requests/src/components/useGithubLoggedIn.tsx#L36

Something like this but more tweaking needed to get it to work with what you have here, but kinda the gist of it:

  const scmAuthApi = useApi(scmAuthApiRef);
  const [isLoggedIn, setIsLoggedIn] = useState(false);

  useEffect(() => {
    const token = (
    await auth.getCredentials({
      url: `https://${host}`,
      additionalScope: { customScopes: { github: ['repo'] } },
    })
  ).token;

Context

We need to use multiple GitHub providers. In order to do this, we followed the Backstage maintainer suggestion of using the scmAuthApi to accomplish this - the original issue on the Backstage side is here:
backstage/backstage#18887 (comment)

We followed the custom SCMAuthApi implementation detailed in the docs here https://backstage.io/docs/auth/#custom-scmauthapi-implementation

For our own plugins we were able to switch from the githubAuthApi to scmAuthApi to be able to view GitHub information from both locations using the appropriate user tokens. Now we'd love to still be able to use Roadie plugins for both as well.