Boostrap fails with encrypted GPG signing subkey

[TristanCottam]

Describe the bug

Bootstrapping fails when specifying an encrypted GPG master key for commit signing which delegates signing to a subkey. Specifying an encrypted GPG master key which is capable of signing directly fixes the issue.

Bootstrap log:

► cloning branch "main" from Git repository "[REPOSITORY URL]"
✔ cloned repository
► generating component manifests
✔ generated component manifests
✗ failed to commit component manifests: openpgp: invalid argument: signing key is encrypted

Steps to reproduce

1. Create an encrypted GPG master key with the Certify capability only.
2. Create a GPG subkey of it with the Signing capability.
3. Run flux boostrap [PROVIDER] with the relevant --gpg-key-ring, --gpg-key-id, and --gpg-key-passphrase arguments.

Expected behavior

Flux successfully bootstraps the cluster.

OS / Distro

Debian 12

Flux version

v2.2.2