build(deps): bump vega-functions

Bumps [vega-functions](https://github.com/vega/vega) from 5.13.0 to 5.13.1.
- [Release notes](https://github.com/vega/vega/releases)
- [Commits](https://github.com/vega/vega/commits)

---
updated-dependencies:
- dependency-name: vega-functions
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>