Bump docs/themes/docsy from cf0c68f to 68aa7b3 (#791)

Bumps [docs/themes/docsy](https://github.com/google/docsy) from `cf0c68f` to `68aa7b3`.
- [Release notes](https://github.com/google/docsy/releases)
- [Commits](google/docsy@cf0c68f...68aa7b3)

---
updated-dependencies:
- dependency-name: docs/themes/docsy
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>