Bump pusher-js from 8.4.0-rc2 to 8.4.0

Bumps [pusher-js](https://github.com/pusher/pusher-js) from 8.4.0-rc2 to 8.4.0.
- [Release notes](https://github.com/pusher/pusher-js/releases)
- [Changelog](https://github.com/pusher/pusher-js/blob/master/CHANGELOG.md)
- [Commits](pusher/pusher-js@v8.4.0-rc2...v8.4.0)

---
updated-dependencies:
- dependency-name: pusher-js
  dependency-version: 8.4.0
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

package-lock.json

@@ -15,7 +15,7 @@
         "postcss": "^8.5.6",
         "postcss-nesting": "^13.0.2",
         "prettier": "^3.7.4",
-        "pusher-js": "^8.4.0-rc2",
+        "pusher-js": "^8.4.0",
         "tailwindcss": "^4.1.18",
         "vite": "^7.3.0"
     }