Consider migrating pass-driver to GPG library

[udf2457]

At present containers/common/blob/pkg/secrets/passdriver/passdriver.go shells out to gpg.

However, it may not always be reasonable to assume that gpg is available. This is perhaps the case with immutable operating systems such as Fedora CoreOS, OpenSuSe MicroOS and others.

Availability of gpg aside, shelling out is also risky from a security perspective, leaving you open to all sorts of side-channel and other attacks.

Meanwhile there are readily available, widely deployed, Go gpg libraries such as ProtonMail/gopenpgp