Bump nox from 2021.6.12 to 2021.10.1 in /.github/workflows

Bumps [nox](https://github.com/theacodes/nox) from 2021.6.12 to 2021.10.1.
- [Release notes](https://github.com/theacodes/nox/releases)
- [Changelog](https://github.com/theacodes/nox/blob/main/CHANGELOG.md)
- [Commits](wntrblm/nox@2021.6.12...2021.10.1)

---
updated-dependencies:
- dependency-name: nox
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/constraints.txt

@@ -1,3 +1,3 @@
 pip==21.1.3
-nox==2021.6.12
+nox==2021.10.1
 poetry==1.1.4