Background

With the change to rem and restructuring of the tokens architecture, we've got rid of font-size-base token in Codex.

But we still have it part of 'mediawiki.skin.defaults.less' and one skin, MinervaNeue is also still providing it.
The current occurrences:
https://codesearch-beta.wmcloud.org/search/?q=font-size-base&files=&excludeFiles=&repos=#Extension:ReportIncident
All of this got surfaced in the work for T366101.

Goal

Rework applications of and remove font-size-base from skin variables

Acceptance criteria

• Use different tokens in current applications
  • Remove from 'mediawiki.skin.defaults.less'
  • Remove from Vector
  • Remove from MinervaNeue