Adds sdw-config 0.5.7 rpm

[conorsch]

Name of package: securedrop-workstation-dom0-config

Same RPM as submitted in #23 , but resigned with the prod key.

Towards freedomofpress/securedrop-workstation#737

Test plan

• Tag in securedrop-workstation repository is correct: https://github.com/freedomofpress/securedrop-workstation/releases/tag/0.5.7
• Build logs are included: freedomofpress/build-logs@5b9ec0d
• CI is passing, the rpm is properly signed with the prod key
• RPM is signed specifically with 2359E6538C0613E652955E6C188EDD3B7B22E6A3, i.e. the "new" 2021 key
• Unsigned RPM after running rpm --delsign (in Debian Stable) on the signed RPM results in the checksum found in the build logs

[eloquence]

FYI, I did not test the fedora-34 PR originally, but I provisioned a staging environment on Thursday and my sys-* VMs were correctly migrated to fedora-34 when I ran the updater.

[sssoleileraaa]

followed test plan and confirmed sha256sum of new rpm: 04c2ef0b2a8eec53032193cbbed6927d12dfc646cf03d6dec613f53141631131