golang.org/x/crypto/openpgp is deprecated

[cablehead]

golang.org/x/crypto/openpgp is currently used to as an optional signing key: https://github.com/google/go-github/blob/master/github/git_commits.go#L27-L50

However this package is now deprecated: golang/go#44226

[hungle92]

Looks like 0.5.0 is released in the following link:
https://pkg.go.dev/golang.org/x/crypto#readme-download-install

It would resolve: CVE-2022-27191

[gmlewis]

@hungle92 - would you like to submit a PR?