build(deps-dev): bump @octokit/fixtures-server from 6.0.7 to 6.0.8

Bumps [@octokit/fixtures-server](https://github.com/octokit/fixtures-server) from 6.0.7 to 6.0.8.
- [Release notes](https://github.com/octokit/fixtures-server/releases)
- [Commits](octokit/fixtures-server@v6.0.7...v6.0.8)

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

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

Author: dependabot[bot]