Bump serde_json from 1.0.64 to 1.0.68 (#672)

Bumps [serde_json](https://github.com/serde-rs/json) from 1.0.64 to 1.0.68.
- [Release notes](https://github.com/serde-rs/json/releases)
- [Commits](serde-rs/json@v1.0.64...v1.0.68)

---
updated-dependencies:
- dependency-name: serde_json
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]