build(deps): Update idna requirement from >=3.7 to >=3.12

Updates the requirements on [idna](https://github.com/kjd/idna) to permit the latest version.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v3.7...v3.12)

---
updated-dependencies:
- dependency-name: idna
  dependency-version: '3.12'
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -15,7 +15,7 @@ google-cloud-datastore
 google-cloud-pubsub
 gunicorn>=25.3.0
 httpx>=0.23.0
-idna>=3.7
+idna>=3.12
 ipaddress
 itsdangerous
 jinja2>=3.1.6