Bump node from 18.20.4-alpine to 21.7.3-alpine

Bumps node from 18.20.4-alpine to 21.7.3-alpine.

---
updated-dependencies:
- dependency-name: node
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Dockerfile

@@ -7,7 +7,7 @@ ARG NODE_ENV
 ARG CI
 
 # --- Define base image ---
-FROM node:18.20.4-alpine AS base
+FROM node:21.7.3-alpine AS base
 
 # Environment
 ARG NODE_ENV