🔒️(front) improve docker image security

Cyberwatch reported security issues with the frontend Docker image.

src/frontend/Dockerfile

@@ -50,19 +50,7 @@ ENV NEXT_PUBLIC_PUBLISH_AS_MIT=${PUBLISH_AS_MIT}
 RUN yarn build
 
 # ---- Front-end image ----
-FROM nginxinc/nginx-unprivileged:1.27-alpine AS frontend-production
-
-# Remove the upgrade part once nginx has published
-# a new image that fixes the CVE related to libxml2
-ARG UID=101
-USER root
-
-# Upgrade system packages to install security updates
-RUN apk update && \
-  apk upgrade && \
-  rm -rf /var/cache/apk/*
-
-USER $UID
+FROM nginxinc/nginx-unprivileged:alpine3.21 AS frontend-production
 
 # Un-privileged user running the application
 ARG DOCKER_USER