Dear Maintainer,

After upgrading fonts-roboto-unhinted from 2:0~20170802-6 to 2:3.016-1,
ligatures render incorrectly. The "fi" and "ffi" ligatures lose the dot
over the "i", so "find" looks like "ffnd" and "affiliate" loses its dot.
A Reddit thread describing the same problem: https://bit.ly/4AkY8Ho

Details:
- Nothing else related to text rendering changed in the same upgrade
  (libfreetype6 2.14.3+dfsg-2 and HarfBuzz were not upgraded).
- hb-shape on Roboto-Regular.ttf shows the ligature is applied
  correctly: [fi=0+1135|x=2+1016]
- hb-view on the same file renders "fix office" with the dot missing.
- Setting font-variant-ligatures: none in the browser fixes it, so the
  problem is specific to the ligature glyphs.

Expected: ligatures render correctly