feat: add base64 encoded private key support

[riley-kohler]

Pull Request

Proposed Changes

This change adds support for a base64 encoded private key which helps to avoid issues with retrieving, setting, and passing around an environment variable value that contains newlines which may be required for some enterprise secret management strategies. The base64 parsing was made conditional to avoid breaking existing setups while allowing the option for those that might need it.

Readiness Checklist

Author/Contributor

• If documentation is needed for this change, has that been included in this pull request
• run npm run lint and fix any linting issues that have been introduced
• run npm run test and run tests
• If publishing new data to the public (scorecards, security scan results, code quality results, live dashboards, etc.), please request review from @jeffrey-luszcz

Reviewer

• Label as either bug, documentation, enhancement, infrastructure, maintenance, or breaking

[ahpook]

LGTM, thanks!

[riley-kohler]

Encountering some issues locally with next build failing if the PRIVATE_KEY env is not set. I would think that the envs shouldn't be necessary until executing the built next bundle but I'll at least make it so that the logic I added doesn't fail if the env isn't set.