Bump idna from 3.7 to 3.15 in /utils/git

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: direct:production
...

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

Author: dependabot[bot]

utils/git/requirements_formatting.txt

@@ -16,7 +16,7 @@ cryptography==46.0.5
     # via pyjwt
 deprecated==1.2.14
     # via pygithub
-idna==3.7
+idna==3.15
     # via requests
 pycparser==2.21
     # via cffi