Bump drf-spectacular from 0.18.1 to 0.20.1

Bumps [drf-spectacular](https://github.com/tfranzel/drf-spectacular) from 0.18.1 to 0.20.1.
- [Release notes](https://github.com/tfranzel/drf-spectacular/releases)
- [Changelog](https://github.com/tfranzel/drf-spectacular/blob/master/CHANGELOG.rst)
- [Commits](tfranzel/drf-spectacular@0.18.1...0.20.1)

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

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

Author: dependabot[bot]

poetry.lock

@@ -17,7 +17,7 @@ django-admin-thumbnails = "^0.2.6"
 PyYAML = "^5.4.1"
 docutils = "^0.17.1"
 django-model-utils = "^4.1.1"
-drf-spectacular = "^0.18.1"
+drf-spectacular = "^0.21.2"
 django-jazzmin = "^2.4.8"
 django-tabular-permissions = "^2.8"
 dj-rest-auth = { extras = ["with_social"], version = "^2.1.11" }