build(deps): bump vega and vega-lite in /docs

Bumps [vega](https://github.com/vega/vega) and [vega-lite](https://github.com/vega/vega-lite). These dependencies needed to be updated together.

Updates `vega` from 5.33.0 to 6.2.0
- [Release notes](https://github.com/vega/vega/releases)
- [Commits](vega/vega@v5.33.0...v6.2.0)

Updates `vega-lite` from 5.23.0 to 6.4.1
- [Release notes](https://github.com/vega/vega-lite/releases)
- [Changelog](https://github.com/vega/vega-lite/blob/main/CHANGELOG.md)
- [Commits](vega/vega-lite@v5.23.0...v6.4.1)

---
updated-dependencies:
- dependency-name: vega
  dependency-version: 6.2.0
  dependency-type: direct:production
- dependency-name: vega-lite
  dependency-version: 6.4.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]