Bump @stripe/stripe-js from 9.0.1 to 9.1.0 in /frontend

Bumps [@stripe/stripe-js](https://github.com/stripe/stripe-js) from 9.0.1 to 9.1.0.
- [Release notes](https://github.com/stripe/stripe-js/releases)
- [Commits](stripe/stripe-js@v9.0.1...v9.1.0)

---
updated-dependencies:
- dependency-name: "@stripe/stripe-js"
  dependency-version: 9.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

frontend/package-lock.json

@@ -11,7 +11,7 @@
   },
   "dependencies": {
     "@stripe/react-stripe-js": "^6.1.0",
-    "@stripe/stripe-js": "^9.0.1",
+    "@stripe/stripe-js": "^9.1.0",
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
     "react-router-dom": "^7.14.0"