Bump @stellar/freighter-api from 4.1.0 to 6.0.1 in /frontend

Bumps [@stellar/freighter-api](https://github.com/stellar/freighter) from 4.1.0 to 6.0.1.
- [Release notes](https://github.com/stellar/freighter/releases)
- [Commits](https://github.com/stellar/freighter/commits)

---
updated-dependencies:
- dependency-name: "@stellar/freighter-api"
  dependency-version: 6.0.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

frontend/package.json

@@ -12,7 +12,7 @@
   },
   "dependencies": {
     "@creit.tech/stellar-wallets-kit": "^1.7.6",
-    "@stellar/freighter-api": "^4.1.0",
+    "@stellar/freighter-api": "^6.0.1",
     "@stellar/stellar-sdk": "^13.3.0",
     "clsx": "^2.1.1",
     "next": "^16.2.6",