chore: remove unused style-loader dependency from package.json and yarn.lock

[cedric07]

Suppression d'une dépendance non utilisée, remontée par depcheck

---

Note

Low Risk
Low risk cleanup: only removes an unused dev dependency and its lockfile entry, with no runtime or business-logic changes.

Overview
Removes the unused style-loader dev dependency from package.json and deletes its corresponding entry from yarn.lock to keep the dependency tree clean.

^{Reviewed by Cursor Bugbot for commit 0f4decc. Bugbot is set up for automated code reviews on this repo. Configure here.}