build(deps): bump gtts from 2.3.2 to 2.5.4 in /application

Bumps [gtts](https://github.com/pndurette/gTTS) from 2.3.2 to 2.5.4.
- [Release notes](https://github.com/pndurette/gTTS/releases)
- [Changelog](https://github.com/pndurette/gTTS/blob/main/CHANGELOG.md)
- [Commits](https://github.com/pndurette/gTTS/compare/v2.3.2...v2.5.4)

---
updated-dependencies:
- dependency-name: gtts
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

application/requirements.txt

@@ -14,7 +14,7 @@ esutils==1.0.1
 Flask==3.0.3
 faiss-cpu==1.9.0.post1
 flask-restx==1.3.0
-gTTS==2.3.2
+gTTS==2.5.4
 gunicorn==23.0.0
 html2text==2024.2.26
 javalang==0.13.0