🔒️(frontend) update alpine packages in production image (#1425)

Force an update of installed package in the image used for the frontend
in production.

src/frontend/Dockerfile

@@ -50,7 +50,13 @@ ENV NEXT_PUBLIC_PUBLISH_AS_MIT=${PUBLISH_AS_MIT}
 RUN yarn build
 
 # ---- Front-end image ----
-FROM nginxinc/nginx-unprivileged:alpine3.21 AS frontend-production
+FROM nginxinc/nginx-unprivileged:alpine3.22 AS frontend-production
+
+# Upgrade system packages to install security updates
+USER root
+RUN apk update && \
+  apk upgrade && \
+  rm -rf /var/cache/apk/*
 
 # Un-privileged user running the application
 ARG DOCKER_USER