add exponential backoff for retrying CNB registry requests

[sophiewigmore]

Summary

Add exponential backoff retry logic to the internal command which queries the CNB registry. This will hopefully reduce the number of automation errors we see from querying CNB registry (429 Too Many Requests).

We update our buildpack.toml files using the jam update-buildpack command, and frequently get notifications of failed updated due to hitting the 429 Too Many Requests error. As far as I know, authenticated requests to the registry are not enabled, so performing a retry when we encounter this issue is probably the simplest path forward. See paketo-buildpacks/php#659 for an example.

I opted to make this change in jam (rather than the workflow itself) because I have encountered this error locally before when using jam.

Use Cases

Checklist

• I have viewed, signed, and submitted the Contributor License Agreement.
• I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• I have added an integration test, if necessary.
• I have reviewed the styleguide for guidance on my code quality.
• I'm happy with the commit history on this PR (I have rebased/squashed as needed).