[2026-05-20] Sync upstream commit 280ee86

## Upstream commit
  - **SHA**: `280ee861eabb500e6c526359d3a5cde3998a5ebf`
  - **Date**: 2026-05-20
  - **Author**: Abdo
  - **Link**: https://github.com/ankitects/anki-manual/commit/280ee861eabb500e6c526359d3a5cde3998a5ebf

  ## Message
  Document additional Debian dependencies (#492)