x11-fonts/fantasque-sans-mono: Update to 1.8.0

This release adds coding ligatures.

• Put distfiles in their own subdir since the filenames are unversioned
• Let make makesum work transparently as normal to ease maintenance

Changes: https://github.com/belluzj/fantasque-sans/releases/tag/v1.8.0
PR: 242019
Approved by: rakuco (maintainer)