fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DEBIAN11-NCURSES-2767191
- https://snyk.io/vuln/SNYK-DEBIAN11-NCURSES-2767191
- https://snyk.io/vuln/SNYK-DEBIAN11-NCURSES-2767191
- https://snyk.io/vuln/SNYK-DEBIAN11-OPENSSL-3368735
- https://snyk.io/vuln/SNYK-DEBIAN11-OPENSSL-5661566

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:18.15-bullseye-slim
+FROM node:18-bullseye-slim
 RUN apt-get update && apt-get install -y --no-install-recommends dumb-init
 ENV NODE_ENV production
 USER node