Bump drf-yasg from 1.21.5 to 1.21.6

Bumps [drf-yasg](https://github.com/axnsan12/drf-yasg) from 1.21.5 to 1.21.6.
- [Release notes](https://github.com/axnsan12/drf-yasg/releases)
- [Changelog](https://github.com/axnsan12/drf-yasg/blob/1.21.6/docs/changelog.rst)
- [Commits](axnsan12/drf-yasg@1.21.5...1.21.6)

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

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

Author: dependabot[bot]

requirements.txt

@@ -20,7 +20,7 @@ git+https://github.com/snyaggarwal/flower # use until https://github.com/mher/fl
 redis==4.5.5
 kombu==5.3.1
 django-elasticsearch-dsl==7.3
-drf-yasg==1.21.5
+drf-yasg==1.21.6
 git+https://github.com/snyaggarwal/django-queryset-csv
 git+https://github.com/OpenConceptLab/ocldev
 coverage==7.2.7