Fix tootctl accounts rotate not updating public keys (mastodon#9556)

This allowed you to brick your system when running that command, because the accounts would continue to advertise the old public key, but sign things with the new one

lib/mastodon/accounts_cli.rb

@@ -309,8 +309,8 @@ def rotate_keys_for_account(account, delay = 0)
       end
 
       old_key = account.private_key
-      new_key = OpenSSL::PKey::RSA.new(2048).to_pem
-      account.update(private_key: new_key)
+      new_key = OpenSSL::PKey::RSA.new(2048)
+      account.update(private_key: new_key.to_pem, public_key: new_key.public_key.to_pem)
       ActivityPub::UpdateDistributionWorker.perform_in(delay, account.id, sign_with: old_key)
     end
   end