Bump concurrently from 8.2.2 to 9.1.0 in /functions

Bumps [concurrently](https://github.com/open-cli-tools/concurrently) from 8.2.2 to 9.1.0.
- [Release notes](https://github.com/open-cli-tools/concurrently/releases)
- [Commits](open-cli-tools/concurrently@v8.2.2...v9.1.0)

---
updated-dependencies:
- dependency-name: concurrently
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

functions/package.json

@@ -28,7 +28,7 @@
   },
   "devDependencies": {
     "@tsconfig/node20": "^20.1.4",
-    "concurrently": "^8.2.2",
+    "concurrently": "^9.1.0",
     "cpx2": "^7.0.1",
     "typescript": "^5.5.4"
   }