Luckily, this one is easy, but I figured I’d put a placeholder here just in case anywhere is curious as to how this works.
The Heroku CLI reads and writes to the same .netrc format that Curl uses with
the netrc gem. Support for GPG has been contributed to it in that if a
.netrc.gpg is present, it will shell out to GPG to read from it.
Did I make a mistake? Please consider sending a pull request.