Bump idna from 2.10 to 3.1 in /src/requirements

Bumps [idna](https://github.com/kjd/idna) from 2.10 to 3.1.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v2.10...v3.1)

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

src/requirements/base.txt

@@ -19,7 +19,7 @@ djangorestframework-simplejwt==4.6.0
 djangorestframework==3.12.3
 extensions==0.4
 graphene-django==2.15.0
-idna==2.10
+idna==3.1
 Markdown==3.3.4
 mccabe==0.6.1
 oauthlib==3.1.0