Bump idna from 3.7 to 3.15

Bumps [idna](https://github.com/kjd/idna) from 3.7 to 3.15.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.md)
- [Commits](kjd/idna@v3.7...v3.15)

---
updated-dependencies:
- dependency-name: idna
  dependency-version: '3.15'
  dependency-type: indirect
...

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

Author: dependabot[bot]

requirements-docs.txt

@@ -5,7 +5,7 @@ certifi==2024.7.4
 charset-normalizer==3.3.2
 docutils==0.20.1
 furo==2024.5.6
-idna==3.7
+idna==3.15
 imagesize==1.4.1
 jinja2==3.1.6
 markupsafe==2.1.3