I don't use GnuPG for anything else anymore, so it's becoming rather
cumbersome to keep setting it up just for the Ansible Vault secret.
Since I use Bitwarden to store the passphrase for my PGP key anyway, it
makes sense to just store the Ansible Vault secret there directly.
Encrypting the vault password with GPG protects the key when stored on
disk and allows it to be accessed non-interactively, as long as the
GnuPG agent is set up correctly.
