Bump stripe from 10.5.0 to 11.4.1 in /backend

Bumps [stripe](https://github.com/stripe/stripe-python) from 10.5.0 to 11.4.1.
- [Release notes](https://github.com/stripe/stripe-python/releases)
- [Changelog](https://github.com/stripe/stripe-python/blob/master/CHANGELOG.md)
- [Commits](stripe/stripe-python@v10.5.0...v11.4.1)

---
updated-dependencies:
- dependency-name: stripe
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

backend/pyproject.toml

@@ -79,7 +79,7 @@ dependencies = [
     "google-api-python-client<3.0.0,>=2.94.0",
     "google-auth<3.0.0,>=2.22.0",
     "argon2-cffi<24.0.0,>=23.1.0",
-    "stripe==10.5.0",
+    "stripe==11.4.1",
     "djangorestframework==3.15.2",
     "l18n<2022.0,>=2021.3",
     "wagtail==6.2.2",