Adds securedrop-workstation-config 0.1.4 package

[emkll]

Status

Ready for review

• Packaging changes described in Provide mime and paxctld configuration for template consolidation securedrop-builder#190
• Build logs are available in freedomofpress/build-logs@8feac8c

Description of changes

Provides the securedrop-workstation-config package that includes the mimetype definitions for various VMs.
Deletes old nightly builds.

I have not opted to create a nightly task to build the config package, since it's rarely updated and is yet another package to clean up. Happy to amend if others think the nighly route is a better approach.

Test Plan

• Package was built correctly (per build-logs)
• Removed packages are correct (any nightly build that was created prior to the beginning of this month)
• Not worth adding securedrop-workstation-config package to nightly CI builds

Checklist

• Cross-link to changes made in securedrop-debian-packaging.
• Build logs have been committed to build-logs.

[zenmonkeykstop]

Reviewed build log and verified checksum. LGTM