chore(deps): update environs requirement from ~=8.0.0 to ~=9.4.0

Updates the requirements on [environs](https://github.com/sloria/environs) to permit the latest version.
- [Release notes](https://github.com/sloria/environs/releases)
- [Changelog](https://github.com/sloria/environs/blob/master/CHANGELOG.md)
- [Commits](sloria/environs@8.0.0...9.4.0)

---
updated-dependencies:
- dependency-name: environs
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -9,7 +9,7 @@ django-extensions
 django-hurricane==0.8.8
 django-polymorphic~=3.0.0
 djangorestframework~=3.12.1
-environs~=8.0.0
+environs~=9.4.0
 gitpython~=3.1.9
 graphene-django==2.15.0
 graphene-federation~=0.1.0