Bump idna from 3.2 to 3.7

Bumps [idna](https://github.com/kjd/idna) from 3.2 to 3.7.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v3.2...v3.7)

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

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

requirements.txt

@@ -20,7 +20,7 @@ django-rest-auth==0.9.5
 djangorestframework==3.12.4
 geoip2==4.4.0
 gunicorn==22.0.0
-idna==3.2
+idna==3.7
 lxml==4.9.1
 maxminddb==2.2.0
 multidict==5.2.0