Bump idna from 3.4 to 3.7

Bumps [idna](https://github.com/kjd/idna) from 3.4 to 3.7.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v3.4...v3.7)

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

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

requirements.txt

@@ -15,7 +15,7 @@ draftjs-exporter==2.1.7
 et-xmlfile==1.1.0
 filetype==1.2.0
 html5lib==1.1
-idna==3.4
+idna==3.7
 isodate==0.6.1
 l18n==2021.3
 openpyxl==3.1.2