build(deps): bump the sanity group with 3 updates

Bumps the sanity group with 3 updates: [sanity](https://github.com/sanity-io/sanity/tree/HEAD/packages/sanity), [next-sanity](https://github.com/sanity-io/next-sanity/tree/HEAD/packages/next-sanity) and [@sanity/preview-kit](https://github.com/sanity-io/preview-kit/tree/HEAD/packages/preview-kit).


Updates `sanity` from 3.68.0 to 3.68.1
- [Release notes](https://github.com/sanity-io/sanity/releases)
- [Commits](https://github.com/sanity-io/sanity/commits/v3.68.1/packages/sanity)

Updates `next-sanity` from 9.8.27 to 9.8.28
- [Release notes](https://github.com/sanity-io/next-sanity/releases)
- [Changelog](https://github.com/sanity-io/next-sanity/blob/main/packages/next-sanity/CHANGELOG.md)
- [Commits](https://github.com/sanity-io/next-sanity/commits/next-sanity-v9.8.28/packages/next-sanity)

Updates `@sanity/preview-kit` from 5.1.24 to 5.1.25
- [Release notes](https://github.com/sanity-io/preview-kit/releases)
- [Changelog](https://github.com/sanity-io/preview-kit/blob/main/packages/preview-kit/CHANGELOG.md)
- [Commits](https://github.com/sanity-io/preview-kit/commits/v5.1.25/packages/preview-kit)

---
updated-dependencies:
- dependency-name: sanity
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: sanity
- dependency-name: next-sanity
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: sanity
- dependency-name: "@sanity/preview-kit"
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: sanity
...

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