Bump orjson from 3.6.7 to 3.6.8 (#2886)

Bumps [orjson](https://github.com/ijl/orjson) from 3.6.7 to 3.6.8.
- [Release notes](https://github.com/ijl/orjson/releases)
- [Changelog](https://github.com/ijl/orjson/blob/master/CHANGELOG.md)
- [Commits](https://github.com/ijl/orjson/compare/3.6.7...3.6.8)

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

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

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

requirements.txt

@@ -10,7 +10,7 @@ mercurial==6.1
 microannotate==0.0.24
 mozci==2.2.1
 numpy==1.21.5
-orjson==3.6.7
+orjson==3.6.8
 ortools==9.3.10497
 pandas==1.4.2
 psutil==5.9.0