- add keys of new Trusted Users: zorin, shibumi, archangegabriel
- revoke keys of ex-TUs: flexiondotorg, dicebot
- revoke Dan's master key

Signed-off-by: Bartłomiej Piotrowski <bpiotrowski@archlinux.org>

These are keys by former developers who have resigned or keys that have been replaced by new ones.

See packager-revoked-keyids for revocation reasons.

We also remove unused signatures from the keys to keep the history more readable