Handle Additional GitHub secondary rate limit failure

[SeanTAllen]

We previously handled secondary rate limit errors, however, it turns out that we aren't getting the exception type that we were seeing then for all secondary rate limits.

This PR updates to handle the generic "GitHubException" that PyGitHub uses. If we get the more generic error and it contains a secondary rate limit message from GitHub, we will handle with our usual "wait and try again" strategy.

[ponylang-main]

Hi @SeanTAllen,

The changelog - fixed label was added to this pull request; all PRs with a changelog label need to have release notes included as part of the PR. If you haven't added release notes already, please do.

Release notes are added by creating a uniquely named file in the .release-notes directory. We suggest you call the file 68.md to match the number of this pull request.

The basic format of the release notes (using markdown) should be:

## Title

End user description of changes, why it's important,
problems it solves etc.

If a breaking change, make sure to include 1 or more
examples what code would look like prior to this change
and how to update it to work after this change.

Thanks.