Unknown signature subpacket: 34 (error 905)

When trying to add a key of type `ED25519` I'm getting the error shown below:

```
❯ keybase pgp select --multi
You are selecting a PGP key from your local GnuPG keychain, and
will publish a statement signed with this key to make it part of
your Keybase.io identity.

Note that GnuPG will prompt you to perform this signature.

You can also import the secret key to *local*, *encrypted* Keybase
keyring, enabling decryption and signing with the Keybase client.
To do that, use "--import" flag.

Learn more: keybase pgp help select

# Algo Key Id Created UserId
= ==== ====== ======= ======
1 255? DFCB1EA39C66CEE8 Joe Banks
2 4096R F9E39305CE213394 Joseph Banks
Choose a key: 1
▶ ERROR key generation error: Unknown signature subpacket: 34 (error 905)
```

## Client details

GPG version: 2.2.29
Keybase version (client + service): 5.8.1

Start by reproducing the failure with `keybase pgp select --multi` using the ED25519 key and the reported GPG 2.2.29 and Keybase 5.8.1 versions. Trace the handling of the generated signature and unknown subpacket 34; done means ED25519 key selection completes without error 905.

Written by the indexing model from the issue text.