Dependencies: Bump akhileshns/heroku-deploy from 3.13.15 to 4

Bumps [akhileshns/heroku-deploy](https://github.com/akhileshns/heroku-deploy) from 3.13.15 to 4.
- [Release notes](https://github.com/akhileshns/heroku-deploy/releases)
- [Commits](AkhileshNS/heroku-deploy@v3.13.15...v4)

---
updated-dependencies:
- dependency-name: akhileshns/heroku-deploy
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/deploy.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: akhileshns/heroku-deploy@v3.13.15
+      - uses: akhileshns/heroku-deploy@v4
         with:
           heroku_api_key: ${{secrets.HEROKU_API_KEY}}
           heroku_app_name: ${{secrets.HEROKU_APP_NAME}}