Bump tar-fs from 3.1.0 to 3.1.1 in /custom-modules/docs-to-pdf

Bumps [tar-fs](https://github.com/mafintosh/tar-fs) from 3.1.0 to 3.1.1.
- [Commits](mafintosh/tar-fs@v3.1.0...v3.1.1)

---
updated-dependencies:
- dependency-name: tar-fs
  dependency-version: 3.1.1
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]