fix: server/Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE319-BUSYBOX-6913413
- https://snyk.io/vuln/SNYK-ALPINE319-BUSYBOX-6928845
- https://snyk.io/vuln/SNYK-ALPINE319-BUSYBOX-6928846
- https://snyk.io/vuln/SNYK-ALPINE319-BUSYBOX-6928847
- https://snyk.io/vuln/SNYK-UPSTREAM-NODE-7430900

server/Dockerfile

@@ -1,4 +1,4 @@
-FROM node:20.12.2-alpine3.19
+FROM node:20.15.1-alpine3.19
 WORKDIR /node-app
 COPY ./server .
 COPY ./client/dist /node-app/dist/public