**Backport:** https://codeberg.org/forgejo/forgejo/pulls/6953
- In the case of parsing an public SSH certificate key, use the underlying key type instead of the certificate type. This means `ed25519-cert-v01` would be seen as `ed25519` type and thus correctly parsed. Certificates do not
change the keysize or otherwise parsing of the key.
- Add unit test.
Co-authored-by: Gusted <postmaster@gusted.xyz>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/6954
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>
Co-committed-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>
cc8a05f693